Author Topic: How to Pass Smog (Read 262715 times)

Yota4life · « **Reply #210 on:** Jan 24, 2010, 01:50:07 PM »

ok i hooked the gauge up to the little vacuum line going from the modulator to the EGR and i was only getting about 1 in. of vacuum at 2500 rpm and once i hit 3000rpm it shot up to 5 in. The pressure coming from the bigger tube on the egr was like nothing. Iv never done this before but i think i was doing it right lol

emsvitil · « **Reply #211 on:** Jan 24, 2010, 02:17:46 PM »

You're tapping into the exhaust, so you want pressure not a vacuum.

You need to see at least a 1/2 PSI. With 2 PSI you'll definitely have EGR working.

Yota4life · « **Reply #212 on:** Jan 24, 2010, 02:23:32 PM »

Quote from: emsvitil on Jan 24, 2010, 02:17:46 PM

You're tapping into the exhaust, so you want pressure not a vacuum.

You need to see at least a 1/2 PSI. With 2 PSI you'll definitely have EGR working.

Ok ill check it right now. But is 1 inch of vacuum enough to engage the egr? might mean the modulator isnt working properly

emsvitil · « **Reply #213 on:** Jan 24, 2010, 02:32:54 PM »

Don't think 1" is enough for the little hoses.

But if backpressure isn't pushing the diaphragm up, the vacuum is vented to atomsphere.

Article 61
http://www.autoshop101.com/

Yota4life · « **Reply #214 on:** Jan 24, 2010, 02:58:47 PM »

Ok i just took the truck around the block and when i was cruising at 25mph (2500rpm) there was zero backpressure. If i really got on it once i hit 3000 rpm it was like 1psi then 4000rpm was almost 3psi. But if i wasent hard on the throttle i was hardly getting any pressure not even 0.5psi. The egr must not of even been working when the smog test was ran. And same goes for the modulator not enough vacuum

Im running a tri-y header to 2.25" exhaust all the way with a plate at the collector. must need a smaller hole in the plate and move it behind the cat.

emsvitil · « **Reply #215 on:** Jan 24, 2010, 03:56:03 PM »

Here's my plate:

Yota4life · « **Reply #216 on:** Jan 24, 2010, 03:59:10 PM »

Thanks for all the help by the way. What size holes are those? I have an iron worker at work so i can make one of those quick

emsvitil · « **Reply #217 on:** Jan 24, 2010, 04:05:05 PM »

Quote from: Yota4life on Jan 24, 2010, 03:59:10 PM

Thanks for all the help by the way. What size holes are those? I have an iron worker at work so i can make one of those quick

1/4" from a sheet-metal punch

Yota4life · « **Reply #218 on:** Jan 24, 2010, 04:26:32 PM »

If i did the math right that will be more restrictive then the 1.25" hole i put in mine.

emsvitil · « **Reply #219 on:** Jan 24, 2010, 04:38:13 PM »

Quote from: Yota4life on Jan 24, 2010, 04:26:32 PM

If i did the math right that will be more restrictive then the 1.25" hole i put in mine.

Just a bit.......

Multiple smaller holes may cause more backpressure than 1 of equivalent area....

Yota4life · « **Reply #220 on:** Jan 24, 2010, 04:43:27 PM »

True. 19 1/4" holes is equal to 15/16 square inches and a 1.25 hole is equal to 1.22 square inches. Should i flip my cat around also? or i can spend 100bucks on a CA legal cat. i couldnt find any info on the internet about the cat i have being Directional.

Edit: maybe i need to check the cylinder compression. It should be really good but it could also be part of the problem

emsvitil · « **Reply #221 on:** Jan 24, 2010, 08:18:36 PM »

I'd flip the cat.

I'd also see about putting the restriction after the cat. (that's what's working for me)

emsvitil · « **Reply #222 on:** Jan 25, 2010, 05:15:11 PM »

Thinking about this, I think having the restriction after the cat may be the key............

The restriction would keep more exhaust gas inside the cat. Having more exhaust gas may enable it to work better (and stay hotter too).

If the exhaust gas is stuck inside for a longer period of time, the catalyst may get a chance to work for the NOX

Yota4life · « **Reply #223 on:** Jan 25, 2010, 05:51:59 PM »

Quote from: emsvitil on Jan 25, 2010, 05:15:11 PM

Thinking about this, I think having the restriction after the cat may be the key............

The restriction would keep more exhaust gas inside the cat. Having more exhaust gas may enable it to work better (and stay hotter too).

If the exhaust gas is stuck inside for a longer period of time, the catalyst may get a chance to work for the NOX

I was thinking that also. Im going to flip my cat and put the restrictor behind it. I was also thinking about how if i had 35" tires instead of 37s the rpms would be higher at 25mph so the egr would engage... or i can just find a better smog guy that will run it in a different gear

emsvitil · « **Reply #224 on:** Jan 25, 2010, 06:07:18 PM »

My last test was at

1649 and 2579 rpm for 15 and 25mph. So the rpms sound right.

What was the HC?

emsvitil · « **Reply #225 on:** Jan 25, 2010, 06:07:58 PM »

And the 25mph test is lighter load than 15 (25% vs 50% load)

Yota4life · « **Reply #226 on:** Jan 25, 2010, 07:01:16 PM »

The HC was 38 (at 15mph) and 19 (25mph) So pretty low considering the max is over 100

Yota4life · « **Reply #227 on:** Jan 25, 2010, 10:15:52 PM »

Also i was looking at the vehicles the cat i have is made for and they are all 5-6 liter engines. Way bigger and also its usually a secondary cat on the exhaust so i just need to buy the correct one an im sure it will pass then.. Im just gonna go for it im tired of screwin around with this an i have a lot of snow wheelin to do

emsvitil · « **Reply #228 on:** Jan 26, 2010, 12:30:40 AM »

Other than being in backwards possibly doing something, I don't think the converter is the problem.

Mine's basically the same:

http://www.jegs.com/i/Dynomax/289/15032/10002/-1#

Yota4life · « **Reply #229 on:** Jan 26, 2010, 07:25:53 AM »

We will see after the next test, i will report back

Yota4life · « **Reply #230 on:** Jan 26, 2010, 02:52:51 PM »

So i emailed Magnaflow, and they checked the drawings on the specific cat i have on right now and its non directional. i can now eliminate that one... Its just not enouph for my motor. Because iv read people getting sky high nox readings then putting the correct cat on and getting a nox reading of around a 100 after

emsvitil · « **Reply #231 on:** Jan 27, 2010, 02:50:56 AM »

I'd hate to see you get a new converter and get the same results.

I really think having the restriction after the converter is the key............

I had been squeaking by on the NOX at 25 before the last test (about the same as your last test, but mines an 86 so I was allowed more).
HC and CO always passed.

Unfortunately I don't know if it was the restriction or a new converter on my last test (previous one broke up inside).

Test results (max/measured)

2005, 15; HC 146/86 CO 1.04/0.04 NOX 1136/892
25; 118/57 1.32/0.05 1222/744

2007, 15; 146/119 1.04/0.07 1136/769
25; 118/87 1.32/0.09 1222/1176

2009, 15; 146/19 1.04/0.00 1136/325
25; 118/14 1.32/0.00 1222/88

Yota4life · « **Reply #232 on:** Jan 27, 2010, 10:03:30 AM »

im going to have it set up correctly, hopefully i get a low nox like you did.

Yota4life · « **Reply #233 on:** Jan 28, 2010, 10:02:19 PM »

So i got my new cat today and heres the difference. New CA legal cat on the right.

Yota4life · « **Reply #234 on:** Jan 30, 2010, 03:40:20 PM »

Got the new cat nice and hot and had it smogged for the 3rd time today. It ran 0 nox at 15mph and 698 at 25mph. I passed!!! Im stoked

emsvitil · « **Reply #235 on:** Jan 30, 2010, 04:50:57 PM »

Now take it off and save it for next time..........

Did you put a restricter gasket behind it?

Yota4life · « **Reply #236 on:** Jan 30, 2010, 06:33:06 PM »

Yeah i did and after checking the egr modulator i dont think it was even working correctly but i still got by....

z 12 · « **Reply #237 on:** Mar 13, 2010, 06:28:10 PM »

hey guy worry about smog i got the connection it cost you more but you will pass for sure

Yota4life · « **Reply #238 on:** Mar 13, 2010, 06:53:45 PM »

Quote from: z 12 on Mar 13, 2010, 06:28:10 PM

hey guy worry about smog i got the connection it cost you more but you will pass for sure

Wheres this? I managed to pass it already.... But my buddy cant get his too pass

kneedownnate · « **Reply #239 on:** Mar 13, 2010, 10:41:31 PM »

Nevermind, not worth commenting on

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