Topic: Emissions fail, advice?

[andykrow]

Gnarly, do you still have functioning EGR on your truck?

[emsvitil]

IT'S NOT LEAN

NOx is from high combustion temp.   The exhaust gas in the intake lowers combustion temp.


The exhaust gas comes from two ports near the #2,3 cylinders.     A header or a wrong gasket could block those ports.


Is the test at idle or on a dyno?

I'm out of town so I can't compare to my 22RE,   but it's possible that the vacuum directly to the EGR won't cause rough running/dying.   
Can anybody with a 22RE test this?

[andykrow [OP]]

The EGR valve test from the 1985 factory service manual says to put vacuum directly to the EGR Valve. If the motor runs rough or dies, the egr valve is functioning correctly. They say if this does not happen, the valve must be replaced.

Are you certain that a header or gasket can block an EGR passage? If you look at the exhaust face of the header there is nothing putting out anything other than the actual exhaust ports that would go into the header. I just took another look at my factory manifold. No passages or anything for EGR.

Also look at this picture


I don't see anything related to EGR anywhere near where a header or gasket go. You can see in the bottom right corner of the head where the EGR passage is.

[andykrow [OP]]

Is the test at idle or on a dyno?

This is a test on a dyno. It runs through the gears twice and on the second pass sits at 60mph for a minute or so in 5th. They gave me a diagnostic printout showing NOx relative to speed through the test. The spikes are occurring at the final third of each gear change. They don't show an RPM but I could hear them driving and I would guess it was between 2.5 and 3.5k. During the 5th gear run at the end there is a fair amount of NOx as well, over the limit. So it would seem to be RPM related, not just during acceleration.

[emsvitil]

EGR is hole is 5 o'clock on #2 and 7 o'clock on #3.

Headers have a notch from EGR holes on flange.

With stock manifolds, the hold opens up into manifold.

[andykrow [OP]]

You, sir, may have solved the egr problem. I put a remflex 7002 gasket on there and it definitely blocks those holes off.

Looking at my Thorley header while it is mounted, I do not see how exhaust could get to these ports, unless the passage is machined into the flange itself. Can anyone confirm before I yank it?

The DT I bought is the thy-542y-o-c which is carb compliant, so it should not block the egr ports.

EDIT: Missed where you said headers have a notch in the flange. GOLD STAR FOR YOU!!

[emsvitil]

Scroll down to EGR

http://www.4crawler.com/4x4/CheapTricks/EngineMods/index.shtml


With headers, you'll definitely need the exhaust restriction plate for the test................

[andykrow [OP]]

All this makes sense. I made a restrictor plate last night and I'll just leave it in there. I am also going to cut the gasket a bit just like he says.

[andykrow [OP]]

I bow before your knowledge of the 22re 

Egr worked splendidly and managed to kill the motor at idle during the test. The gasket was indeed the problem. Thank you for saving me from a stupid purchase!

The DT egr cutout in the flange looks huge. No way does it need to be ground like 4crawlers LCE header. I probably didn't even need to cut the gasket but I did for good measure anyway.

[emsvitil]

 


Now for the test..............

[Snowtoy]

Egr worked splendidly and managed to kill the motor at idle during the test. The gasket was indeed the problem. Thank you for saving me from a stupid purchase!

[Gnarly4X]

First, I thank andykrow for posting his issue and question here because without reading about these of issues, many people may struggle with lots of frustration, time and money to find a fix.

I especially thank “Dr. emsvitil” for his time and generosity to continuously share his knowledge and experience here to help us diagnose and figure out the answers to these common questions on the 22RE.  In my experience or inexperience, and reading so many posts about the 22RE, its very obvious that this engine is WAY more complex with its ECU-controlled design, than the 22R, and requires lots knowledge on the components that control the AF and other functions.

snowtoy, although he disappears for awhile, has also made many contributions to help diagnose and provide great information...Thank you!

There are obviously others who post great stuff, and you know who you are... thank you.

As I try to follow and educate myself from the posts, I would like to make sure I understand what was going on and how the changes and testing was done to uncover the problem with the EGR valve.

So do I have this right?

The EGR valves needs to have a certain flow from a partial amount of exhaust coming from the head via the exhaust manifold.

The Rimflex gasket used by andykrow was causing a partial blockage of flow.

The LCE header, as described by the comments on Roger’s site in the link that was posted.  From the small notch that he describes that is on his LCE header…

Quote:  “On the LC header, there are little notches milled into the header flange to send gas to those two ports. But I found two problems with that design that caused flow restrictions due to the small depth of those passages. One was that the header tube weld bead protruded into that milled notch. So I took the time to grind down that weld bead and even round over the inside edge to aide gas flow into that EGR port. The second issue was the thin web of gasket material between the main exhaust port and the EGR port.  Over time, carbon builds up on that gasket and makes it thicken and intrude into the gas passage. So I simply took a new gasket and cut out the web of material between the main and EGR port, shown in red below. The basic idea is to make the #2 and #3 ports have a larger opening. In the stock cast iron exhaust manifold, there is a dedicated gas passage cast into the manifold that takes gas from the exhaust runner back to the EGR port hole. But the way the LC header is set up, they rely on that small passage into the flange and thus there is no need for a gasket in between the two holes, as there is no contact between the flange and head at that point.”  Unquote.

As many of us know Roger’s contributions to the early Toyota trucks and 4Runners owners over many years has been incredible!

From Roger’s post, I am surprised that LCE failed to properly design its highly touted header to correctly supply the necessary exhaust flow to the ports for the EGR.  Perhaps they have corrected that apparent design flaw. That is one of reasons I have stated before when discussing aftermarket suppliers, that just because an “expert” says it or makes, doesn’t mean its right – there are many many examples of this.

It’s nice to know that the Doug Thorley header appears to be correctly designed for the exhaust flow to the EGR system.

I will also test my EGR valve see if it’s working properly.  Right now I’m running the stock exhaust manifold and exhaust manifold gasket supplied by the engbldr kit.

 andykrow…I commend you for your tenacity to find the problem, while sharing your experience here.  I hope you have fixed your engine so it will pass your state emissions test and get back to enjoying your new rebuild.

I am also hopeful that the 261C cam is NOT the problem and causing a lean mixture?

I apologize for my wordy posts.

Gnarls.

[andykrow [OP]]

PASSSSSSSSSSSSSSSED IT!!!    lots of that after work tonight, haha.

This time it rocked it. NOx half the allowable limit and everything else on the low end of the scale. I knew I was going to get a free retry so I took out the baffle this time just to see how it went. No issues at all. I also left my tweaked AFM settings as they were (two clicks rich, two turns rich on the screw) and left my timing at zero during the test. I put it back up to 5 BTDC immediately after and now she's driving like a beast.

Interestingly, HC and CO, while still very low, were three times higher than they were during the runs without the EGR working. CO2 was nice and high indicating a good mixture, not lean.

emsvitil, what header do you have? I seems reasonable that something like the LCE, where the EGR notch may be too small, requires a bit of extra backpressure to force exhaust gasses through there. I thought since mine killed the motor so easily at idle that it would be fine at speed without a baffle. My reasoning was at idle there would be the least amount of pressure from exhaust, compared to 3000 rpm and up, where the EGR system is supposed to kick in.

So for reference, the Remflex I had is the 7002. It COMPLETELY blocks the egr passage in the head. They also make the 7010 that does have the egr passages in it. I actually think I am going to pick that one up and use it instead of the crappy engnbldr gasket I have in there right now that has a slight leak. (Probably from mangling it a bit while cutting out a bit of extra gasket between the EGR holes and the main ports.) I actually really like the fact that the remflex uses low torque on the studs. (20 instead of 35 ft/lbs.) I do not think I will cut out any of the next gasket I use, the DT seems to have plenty of space.

So, I must admit that while I was hating on emissions at the beginning of this adventure I am glad to have gone through this. My truck is running better than it ever has and I assume I fixed some vacuum leaks along the way. I have a ton of low end grunt and the idle is rock solid.

Also, a note for EGR. I do not notice any difference or loss of power in the upper rpms. I do not know why people disable this system, maybe just for some myth that EGR will rob horsepower, or that if a system is there to help emissions it must be from big brother trying to control our lives. My butt dyno tells me it does nothing to hurt the power output, and lowering cylinder temps can ONLY be a good thing for the motor.

So, to recap the EGR test. To make sure the valve works, put vacuum direct to the top nipple on the valve during idle. It does not need a lot of vacuum to trigger the valve - mouth pressure was easily enough. Motor should run REALLY rough and want to die. If it passes that test, put a T into the line from the truck that is supposed to connect to that top nipple and put a vacuum gauge on it. With a warmed up truck, you should see vacuum at 3000 rpm or so. If you see vacuum, your EGR system is working, it's that simple. On my motor (85) this is all mechanical, no electronic control. The EGR gets vacuum once the throttle butterfly has passed the upper ports on the throttle body, thus exposing them to manifold vacuum.

Thanks to everyone for chiming in and helping me out! Great ideas, great diagrams, great everything I'm putting collector plates on this thing so I don't have to do this again for five years, haha.

[andykrow [OP]]

I apologize for my wordy posts.

I like to read and write wordy posts. No complaints from me

[Gnarly4X]

Geezzzzz..  I love happy endings!!

Great thread on EGRs and issue with exhaust headers and gaskets!!!  Extremely valuable information in my book.

I can't wait to get my rebuild working right.  I have had some delays with medical issues, so I can't work on my truck.... bummed out.

As soon as I can, I will check out the EGR and verify its working properly.

Regarding the gaskets and LCE header... I can't find anything from Remflex or LCE site that discusses that issue that
Dr. emsvitil and Roger Brown identified and you confirmed.  And, I have to believe this problem has happened before.  I used the exhaust manifold gasket that came with the gasket kit from engbldr.  I have read posts that it doesn't last long. But I didn't take the time to order the Remflex.  When I use the stock exhaust gaskets, I spray Permatex copper on both sides with two coats.  As I have posted on my engine build thread, I do not use the factory stock clamping style nuts.  See photo.  I use never-seize on the studs for nuts and red Locktite for the studs inserted in the head.  I have found that whenever I have to remove the header or the exhaust manifold, the gasket will usually NOT reseal and leaks, so I just replace it with a new one.  I also do 3 or 4 checks for tightness on the nuts.  After a 100 miles or so, the nuts will almost always be tight and I don't have any exhaust leaks at the head.  I have a thin lock nut that I put on after initial series of checks and re-torques.

Gnarls.

[andykrow [OP]]

Hope you get to working on your truck soon!

Remflex's description of the 7002 says "for header applications." I asked them at the time if I wanted the 7002 or 7010 and never heard a response, so I just went with the 7002. The 7002 says it has "EGR Gaskets" included but I think they are talking about external piping for carb applications, not the manifold gasket (clearly.) It is a little misleading.

I noticed during this swap that the shop that assembled this stuff used 4 bolts and 4 studs on the exhaust, rather than 8 studs. With the Remflex it did not matter, it only gets torqued to 20 ft/lbs. But, with the "normal" gasket, I was a bit scared to torque up to 35 ft/lbs. I don't think you can tighten that far into aluminum although I could be wrong. I did not want to risk it. So, there is a slight leak at the flange that maybe would be gone at 35 ft/lbs, i don't even notice it with the radio on. But I will order up some toyota studs when I get the 7010 gasket. Another benefit of the remflex is that it is a thicker gasket, easily double a stock gasket, so if you cut out the unnecessary gasket material between the exhaust and EGR ports, you will be making an even larger channel for the EGR flow.

I plan on using a lock washer and standard nut instead of the crimped self-locking nuts.

[Snowtoy]

PASSSSSSSSSSSSSSSED IT!!!    lots of that after work tonight, haha.

Interestingly, HC and CO, while still very low, were three times higher than they were during the runs without the EGR working. CO2 was nice and high indicating a good mixture, not lean.

Likely caused by the additional 2 clicks in the AFM and the recirculating of exhaust gases into the intake.  Also, if you have a high flow cat, it may not get hot enough to burn the HC's and CO's under test conditions, the baffle that emsvitil posted will slow the gas flow down, allowing the cat to burn hotter. 

So, I must admit that while I was hating on emissions at the beginning of this adventure I am glad to have gone through this. My truck is running better than it ever has and I assume I fixed some vacuum leaks along the way. I have a ton of low end grunt and the idle is rock solid.

Also, a note for EGR. I do not notice any difference or loss of power in the upper rpms. I do not know why people disable this system, maybe just for some myth that EGR will rob horsepower, or that if a  system is there to help emissions it must be from big brother trying to control our lives. My butt dyno tells me it does nothing to hurt the power output, and lowering cylinder temps can ONLY be a good thing for the motor.

I think those that stripe the emission stuff, usually fall into one of two camps, "it robs HP", or "too cheap to replace it when it parts fail", the second I understand, if you don't have to pass a test every other year or so why would you spend a couple hundred on replacement parts or hours chasing down a problem.  However, what most people forget is that unlike the engines of the mid to late '60's, where smog equipment was just slapped on to meet the newly introduced emission standards, engines since then have been designed along with the emission equipment, and simply deleting the equipment without correcting for it, usually ends up having a negative effect on performance.

[andykrow [OP]]

Likely caused by the additional 2 clicks in the AFM and the recirculating of exhaust gases into the intake.  Also, if you have a high flow cat, it may not get hot enough to burn the HC's and CO's under test conditions, the baffle that emsvitil posted will slow the gas flow down, allowing the cat to burn hotter. 

I think those that stripe the emission stuff, usually fall into one of two camps, "it robs HP", or "too cheap to replace it when it parts fail", the second I understand, if you don't have to pass a test every other year or so why would you spend a couple hundred on replacement parts or hours chasing down a problem.  However, what most people forget is that unlike the engines of the mid to late '60's, where smog equipment was just slapped on to meet the newly introduced emission standards, engines since then have been designed along with the emission equipment, and simply deleting the equipment without correcting for it, usually ends up having a negative effect on performance.

Strangely though on the pass before that failed, I did have the afm set at 2 clicks. On this run as well I did much more of a warmup, driving around for 30 minutes or so to try to get the cat hot. It is a high flow cat. Even though HC and CO were three times higher than previous passes they are still only 10% of the allowed limit. Very low and I am not concerned about it at all.

I can understand not wanting to replace a $200 valve if you don't have to. But, I bet if you just yank it off every 50k miles and clean it the valve will last forever.

I wonder if there is any long-term danger to running without the EGR. Like you said, Toyota likely designed this as part of a system, they didn't just slap the EGR on there to get through emissions.

I've been reading a bit about EGR, and it seems it can actually increase power. It requires the throttle to be slightly more open for a given power output, which can make the throttle operate more efficiently. Also, the reduced cylinder temps can reduce the amount of heat soak happening, increasing efficiency by having more heat go into forward motion rather than absorbed into the cylinder walls. Interesting stuff (to me at least, haha.)

Anyway my butt dyno confirms no ill effects of a functional EGR.

[Gnarly4X]

Hope you get to working on your truck soon!

Remflex's description of the 7002 says "for header applications." I asked them at the time if I wanted the 7002 or 7010 and never heard a response, so I just went with the 7002. The 7002 says it has "EGR Gaskets" included but I think they are talking about external piping for carb applications, not the manifold gasket (clearly.) It is a little misleading.

I noticed during this swap that the shop that assembled this stuff used 4 bolts and 4 studs on the exhaust, rather than 8 studs. With the Remflex it did not matter, it only gets torqued to 20 ft/lbs. But, with the "normal" gasket, I was a bit scared to torque up to 35 ft/lbs. I don't think you can tighten that far into aluminum although I could be wrong. I did not want to risk it. So, there is a slight leak at the flange that maybe would be gone at 35 ft/lbs, i don't even notice it with the radio on. But I will order up some toyota studs when I get the 7010 gasket. Another benefit of the remflex is that it is a thicker gasket, easily double a stock gasket, so if you cut out the unnecessary gasket material between the exhaust and EGR ports, you will be making an even larger channel for the EGR flow.

I plan on using a lock washer and standard nut instead of the crimped self-locking nuts.

My experience with my 3 22s may be different from others.  First, I do not torque the header nuts to spec.  Just like I do not torque the spark plugs to 25 psi, for spark plugs I do not use any never-seize, just a very light spray of silicon on just the top of the threads.

On the heads and nuts....I have posted my opinion on this a number times on a number Toy sites.  I do not believe the bolts into the head is better in any way.... unless someone can explain the benefits over stud/nuts, but I always keep an open mind.  The alloy head and the steel studs have different coefficients of thermal expansion and cause the alloy threads inside the head to "powder" and corrode. When you torque the factory clamping style nuts, they will twist the stud inside head.. now your screwed!!  The main reason people experience header or manifold leaks is they don't take the proper steps to check and keep the nuts tightened or there is flatness problem with the head or header/exhaust manifold - I switched to non-clamping hex nuts and lock washer years ago.  I'm not saying the factory nuts don't work for some people, they just never worked for me.  And having to drill-tap-helicoil the exhaust threads in 22 head on the truck is extremely painful for me.

Regarding the DT header, unless they have changed, I had to have the mating flange to head machined to make them flat.

I've been teased about my perceived over-analyzing and excessive question-asking most of my life, but I'm too often not completely satisfied with the incomplete information I get from many sources - especially in the aftermarket supply world in the automotive industry.

Perhaps I'm a slow-learner... even though I have 5 years of college, a Mensa IQ, and extensive ongoing self-education, I'm an old fart.  Being "smart" doesn't mean you know how to properly rebuild a 1986 22RE engine... ask me how I know! 

That's just my opinion - it may be worthless.

Gnarls.

[andykrow [OP]]

This will be my third DT header and this is the first one that has not completely sealed for me. But, I did mess up the gasket a bit and I only torqued to 20 or 25 ft/lbs so I am not surprised, I have no reason to think it's the flange. With the Remflex is was completely sealed. Of course, that is part of their thing, the gasket is supposed to compress to half it's starting thickness to make up for warped flanges. I wonder how they hold up over time?

As for bolts into the head, that cannot be good. I do not want all that twisting force going onto an aluminum thread. Looking up a recommended m10 torque rating into aluminum I found 19 ft/lbs recommended. But, with using a stud that twisting force all happens at the stud/nut interface so we can go higher.

Since Remflex says to go to 20 that is what I will do.

Another issue would perhaps be corrosion caused by aluminum and steel simply contacting each other. I notice the OEM Toyota studs I ordered have the head side fully dipped in red stuff (assume loctite or similar.) Perhaps they put so much on to keep aluminum/steel contact to a minimum.

[emsvitil]

emsvitil, what header do you have? I seems reasonable that something like the LCE, where the EGR notch may be too small, requires a bit of extra backpressure to force exhaust gasses through there. I thought since mine killed the motor so easily at idle that it would be fine at speed without a baffle. My reasoning was at idle there would be the least amount of pressure from exhaust, compared to 3000 rpm and up, where the EGR system is supposed to kick in.

Don't have a header.     I've contemplated buying/making one (I went as far as buying the exhaust flange).      So I wanted to know how the EGR system worked because I was always just squeaking thru on the smog test with just a cat-back exhaust system.

CA actually made it harder (lower threshold) the same year I first put the restrictor in the exhaust (I would have failed with my historic readings with NOx).

Note:  the squeaking thru was just with the NOx...........

[emsvitil]

EGR articles:

http://www.autospeed.com/cms/article.html?&A=112729

http://www.autospeed.com/cms/article.html?&A=112730

http://www.autospeed.com/cms/article.html?&title=EGR-Comeback&A=112612

[Snowtoy]

Strangely though on the pass before that failed, I did have the afm set at 2 clicks. On this run as well I did much more of a warmup, driving around for 30 minutes or so to try to get the cat hot. It is a high flow cat. Even though HC and CO were three times higher than previous passes they are still only 10% of the allowed limit. Very low and I am not concerned about it at all.

Your exhaust temps were higher before, which could have helped to burn off more HC/CO's, i.e., every action causes an equal but opposite reaction.  At any rate, with them being well below average, I wouldn't be concerned either.

I can understand not wanting to replace a $200 valve if you don't have to. But, I bet if you just yank it off every 50k miles and clean it the valve will last forever.

My thought as well, not a lot to one, the main problem seems to be the carbon build up with the small stem port. 

I wonder if there is any long-term danger to running without the EGR. Like you said, Toyota likely designed this as part of a system, they didn't just slap the EGR on there to get through emissions.

I've been reading a bit about EGR, and it seems it can actually increase power. It requires the throttle to be slightly more open for a given power output, which can make the throttle operate more efficiently. Also, the reduced cylinder temps can reduce the amount of heat soak happening, increasing efficiency by having more heat go into forward motion rather than absorbed into the cylinder walls. Interesting stuff (to me at least, haha.)

Likely only real danger is to the pocket book due to reduced fuel economy, and the difference in performance that you experienced. 

Anyway my butt dyno confirms no ill effects of a functional EGR.

That is the true test w/mods, if you can't feel the difference in performance, the modification is as helpful as 'speed stickers".

[Gnarly4X]

Your exhaust temps were higher before, which could have helped to burn off more HC/CO's, i.e., every action causes an equal but opposite reaction.......

Hi Snowtoy...  although I get your point about exhaust temps, "every action causes an equal but opposite reaction" refers to Newton's Laws of Physics regarding motion, not gases.  I think you meant the Law of Gases of Robert Boyle as most often discussed... i.e, doubling the absolute temperature of the air in an engine cylinder will double its volume.  Beyond that, the chemistry of gasoline combustion and AFR inside an engine cylinder gets complex quickly... at least for me.

Gnarls.

[Gnarly4X]

....
I can understand not wanting to replace a $200 valve if you don't have to. But, I bet if you just yank it off every 50k miles and clean it the valve will last forever.

That statement, I believe, is spot on.  And, arguably the most important aspect and requirement to keep these engines alive and well for extended trouble-free mileages- PREVENTATIVE MAINTENANCE.

Since my first 1986 22RE Longbed pickup, and owning 14 Toyota vehicles, including a Supra, 4 trucks, and a Lexus IS250, I firmly believe that with proper and diligent preventative maintenance many failures and unexpected costs can be avoided.

Of course everyone has a different concept of cost of vehicle ownership, investment, and value.  During my 8 years of very active sandrailing, I was always amazed at the guys that would arrive at the dunes unprepared, consequently many of the guys would spend lots of time being nice and helping the guy fix something that should have been done before the planned 3-day week end get-together. As result, many of the members of group's play time on the dunes was drained by the guys who didn't do the prepping they should have.  Although it was pretty much a common occurence, I still think those regular perps were rather selfish and lazy.  Not wanting to be "that guy", I spent 1 or 2 weekends before the trip going over every square inch of my sandrail, refreshing the air filter, checking and changing oil, checking nuts & bolts, trickle charging the battery, checking lug nuts, tires for leaks. Then I made sure the same preventative maintenance was done to my tow truck and travel trailer.

At times I gave someone one of my spare parts, who "needed to borrow it" to fix a problem.  Sadly sometimes I never got  one back, and I would have to go buy another one replace my spare parts kit.

That's just my opinion - it may be worthless.

Gnarls.

[Gnarly4X]

Hey andykrow,

Now that you have your engine tuned-up, I am eager to see what you think about your spark plugs reading, and would appreciate a close-up photo.  What spark plugs are you running?

Also, I'm very interested in what your compression is reading.

Thanks,

Gnarls.

[andykrow [OP]]

Hey Gnarls,

Getting pretty busy at work so I have less wrenching time.

I'll pull the plugs soon and see how they look. I don't have a compression tester so I don't really have a good way to do that. If I can find a deal on one maybe I'll pick it up and give it a run. Should let me know if those rings are sealed up nice.

I put the Remflex on there and the exhaust leak is worse than before. I had trimmed out some gasket between the EGR holes and the main ports, and then torqued to 25 pounds. Don't know if that was enough to over torque it and cause a problem, or if I never should have cut it at all. They say 20 pounds, I wouldn't think 25 would cause an issue? After the leak I went up to the factory 35 pounds and that did nothing to it. Going to see if I can get my money back from them.

I think I am going to pick up the Napa gasket today and some ultra copper and give that a shot. The Napa one looks good enough I guess, it'a graphite or carbon with metal around the exhaust ports.

I'm also going to completely pull the DT out of there as well and see if it looks warped or not. I'll get it trued up if I need to but hopefully that is not the issue.

[andykrow [OP]]

Welp, laying in the snow melt under my truck isn't much fun, but it's done. Noticed the Remflex 7010 has a hole between the two middle lower stud holes. Apparently this is a channel to the EGR passage (I think) as it was clear exhaust was coming out of this. The DT header has a hole there too, not sure why, but this was the cause of the leak.

So, one Napa gasket later and I'm quiet again

So, for those with a header that also need to run an EGR, there does not appear to be a Remflex gasket that will work for you. Lesson learned.

EDIT: Doing a little internet searching, I am seeing some header setups where a bolt is threaded into this center hole. Didn't think to check and see if this hole was threaded or not. Does anyone know if it comes stock threaded? Sort of a bummer if I could have just tossed a bolt in there.

[emsvitil]

Found this:






Looks like on stock manifold hole is covered....

[andykrow [OP]]

Got in touch with Tod over at Engnbldr. He let me know that hole is threaded the same as the rest of them M10x1.25, and said the reason is for different manifold styles. I definitely had exhaust coming out of it...

Anyway I will probably toss in another Remflex since I still have a slight leak with the gasket I got at Napa. Should be cheaper than getting the flange trued by a shop. I like the lower torque setting and hopefully that will mitigate the stripped-thread syndrome these heads always seem to get.