How to Pass Smog

[dgrant71]

Ya i have herd about getting the cat hot but never herd of it working.

[Sleeve of Wizzard]

I PASSED! I knew my 87 4 runner was gonna give me trouble but I made it. Thanks a bunch to this thread I couldn't have done it without it. So the truck runs great but I know the cat is bad. I did a tune up (plugs, wires, cap rotor, oil change, air and fuel filter) set the timing and idle, 750 and 5 degrees. looked over all the vacuum lines to check for leaks. I ran some Chevron 91 octane with RXP gas kicker through her then 3 gallons of 76's 87 octane with a bottle of 90% isopropyl the day of the test. ran the out of her to get her nice and hot and went to a smog shop in down town Fresno that my friend recommended.

  The shop is awesome! It's called Smog Auto, located on the corner of divisidero and Effie. Sign in front says "no pass, no pay". They do a free pretest and let you know if it will pass and what you need to fix. mine was boarderline and he said it could go either way. He ran it and it and the sniffer wouldn't read properly due to holes in my exhaust after the muffler. They cut the pipe after the hanger so it ends above the rear axle and it fixed the problem. He started the test over and took his sweet time getting the cat hot. I barely squeaked by and it was all thanks to the smog tech, it wouldn't have passed it if he didn't do everything that he did. If your gonna smog your truck go here!

  Here are my numbers :

                    | C02    | % 02  |          HO (PPM)         |             C0%          |         NO (PPM)          |    
------------------------------------------------------------------------------------------------------
Test    | RPM  | Meas  | Meas  |  Max   |  Ave  |  Meas |   Max  | Ave | Meas |  Max  |  Ave  |  Meas  |    
------------------------------------------------------------------------------------------------------
15 Mph | 1668 | 14.54  |  0.08  |  131   |     48 |      95 |  0.61  | 0.09 | 0.60 |  760   |  342  |    100  |
------------------------------------------------------------------------------------------------------
25 Mph | 1655 | 14.57 |   0.06  |  103   |     36 |      90 |  0.77  | 0.11 | 0.53 |  784   |  330  |     67   |
------------------------------------------------------------------------------------------------------


 

[zeros215]

you know the emissions testers arent aloud to kick you out if you exhaust is just unbolted. Just seperate the end of the cat from the pipe a tiny bit and bam passed! haha easier then doing all that other stuff.


Oh and dont remove the bolts completly or its considered not intact

[Slayer]

Great thread, I found it a day late. My 85 truck failed 2 days ago, they said it was running rich. I checked my manual and from what I see there isn't a way to adjust fuel mixture, correct? I changed the plugs and I'm going to try all the suggestions on here, I hope that fixes it.

[jslater2]

anyone know if having a safari snorkel will pass the visual inspection for smog in California?

[krelnydelnky]

I have an 81 toy and i threw an 87 carbed 22r in there with plans of making it fuel injected. do you think i would have to go get it reffed before i could smog or do you think they wouldnt notice. the problem is that the smog setup for an 81 is completely different. lemme know what you guys think

[TURBO]

i have heard that if the engine your swapping in, is within 5 years, it's still only subject to the original vevicle's smog requirements, but over 5 years, it's subject to the year of the engine being swapped in.

so in your case, you would need to meet 87 carb'd emissions... ie. you need all the 87 smog components to be present and functional

but that's just what i heard... don't hold me to it

[Slayer]

Big thanks for the advice in this thread. I failed smog due to high CO eariler this week, before I found this thread, and I thought I was screwed. Changed the oil, plugs, put a bottle of alcohol in the tank, and then went to a different place, one that a buddy recommended. On the way down there I drove the hell out of her and left it running while I waited for my test. I pretty sure the tech tested the truck in 4th gear, but anyway I passed very quickly. Before my CO was 2.66 and 2.72, today it was .52 and .49, huge difference. Anyone in Orange County, looking for smog, I went to Smog Pros on the corner on La Paz and Marguerite. Thanks again!!!!

[8D3TOY]

Well after a few years of enjoying worry free smog checks (I spent tons of cash getting it legal) I failed mine today.

RPM    %C02     %02   HC(PPM)     CO%     NO (PPM)
1760    15.2       0.1       24          0.00        1276   (MAX 1060)  FAIL
1782    15.2       0.1       18          0.00          828   (MAX 962)   PASS

I also failed the gas cap, bu I protested because he could not get it to fit his machine so he held it on with a rag.  Then I think he tore the rubber seal off part way to show me it was bad.

My main issue is his machine was having problems and my Toyota sat at idle for 40 minutes before he continued the test, do you think it loaded up at idle and was dirty?
I think the test should have been aborted.
I went and got a new cap and a bottle of the recommended RXP Gas Kicker and went back after a 33 mile freeway jaunt to work in the RXP and get it hot and wouldn't you know it his machine was down and he is having it calibrated tomorrow morning so I am first in line after that.  I will update the results after.

[8D3TOY]

Passed,

RPM      %C02   %02   HC (ppm)  CO%      NO (ppm)

1732      15.2     0.1        19        0.01        62 Pass
1747      15.1     0.0        27        0.17        49 Pass

So if you look at my #'s above from yesterday they are all pretty close except the NO(ppm) so can this be attributed to the RXP gas kicker?  It calims to reduce NO and I used it and mine are considerably lower.

One thing I read is that getting the motor hot versus being at operating temp may have a worse effect on NO as it is a product of  high combustion chamber temps.  I had added the RXP and went 30+ miles to make sure it was well intergrated into the fuel system, then it sat overnight.  I then started and warmed it up making sure the choke was completely off and took it for a casual drive, not hot but normal temps and you see the result.
RXP has my vote but I really can't say that it did anything.

[emsvitil]

I think it was more likely that the cat cooled down too much on the first test...........

[8D3TOY]

I am not sure because the next day that it passed it was not hot and sat in the parking lot for a bit before the test and again it idled for about 10 min while he was messing with a volvo so like I said cant tell if the RXP helped or not.  Sure is nice having all the smog junk there and functioning.

[71Dart]

I just register my trucks in a county that doesnt run smog so I dont ever have to worry about it.

[CrazyYota]

I have to smog my junk this month but I don't think it is going to pass. It smells like gas just idling in the driveway.    I think its running rich.   

[87hillbillyoter]

ok guys i got a question for yall- my truck passed with flying colors....at idle. then, at 2500 RPM, the CO was at 1.8-2.4. whatever that means. but it has to be at 1.5 or less to pass. what can i do to fix this? i bought a new OE o2 sensor, will be putting that in tomorrow. also, changed the oil, ran seafoam through it, newer plugs, newer air filter. any suggestions? thanks guys   oh and its carbed (22r) by the way

[87hillbillyoter]

anybody??

[91 ex-cab]

Whats your timing at? I had the same problem on my old truck but taking the timing down made it pass no problem. It ran like a dog after that, but I think the new owner took it back up and got it dialed.

[87hillbillyoter]

no idea. i dont even know how to check it haha.

[91 ex-cab]

no idea. i dont even know how to check it haha.

If you have the results from the test it will say on there.

[87hillbillyoter]

Ok well it passed!! yeehaw! what i did was i got a new o2 sensor, this thing was black. dont think its been replaced since 1987. i also ran seafoam through it again, and i sprayed a whole can of carb cleaner in the carb. cleaned the air filter again, and  i put a bottle of rubbing alcohol in the tank. im pretty sure that was the reason i passed. but now, my truck is finally registered and its been like a year and 10 days since i bought it haha

[CrazyYota]

I just smoged my junk today and it passed!!!  I did a tune up adjusted the timing back to stock and ran half a tank with RXP gas kicker. 

[konarider1993]

Or you could just move to a place like Oklahoma or Arkansas without all of the stupid tree huggers and smog tests.

[86YotaKing]

I have a lot to try, thanks for the info

[Tofudude]

anyone know if having a safari snorkel will pass the visual inspection for smog in California?

my instructor told me most places won't care as long as their is some sort of stockish looking filter between it and the intake

[elrob20]

Thanks for the info

[Japjeep]

i need some help too! took my truck down for smog and it failed on both hc and co. came home did a tune up and replaced the o2 sensor. took it back down for retest and it passed everything but hc at 2500 rpm's. it only needs to come down 25 points to pass! anybody got any ideas?  its a 86 22re.  thanks for any suggestion.

[emsvitil]

How old is the cat?

[ajordan1975]

wouldn't the best way to"pass smog" be to move out of California??   

[Rocksurfer]

A note for OBD II, something I found out yesterday. I had the wife take the dually for the bi-annual sniff, I had to jump it since the batteries had gone dead from sitting, they couldn't smog it due to the computer having been reset from the dead batteries. She had to drive it 30 miles for the smog to be completed. What a bunch of bs.

wouldn't the best way to"pass smog" be to move out of California??   

I've thought of this one too, was going to have Tice register my 86 truck in AZ. to avoid smogging but when it blew up I sold it.

[mrtt999]

   I have failed the smog 2x in a row now...  High CO and HC  The second attempt far worse.  I am ready to give up!  '84 SB Std. Cab 22r  - Before I went in the first time I replaced the spark plugs, wires, oil/filter, adjusted the timing to 5 BTDC, and replaced several bad vaccuum hoses.  I also checked the float bowl fuel level, which was in spec. according to the '85 FSM I am using as a reference.  Fuel lines are relatively new, and the carb looks good, no visible leaks/issues.  The truck usually starts on the first crank, even cold after sitting a day or two, and runs very good and idles fine.  It has the Aisan carb with the idle mixture plug missing from PO.  I checked the idle mixture screw and it is ~2 turns out.  Idle is currently at 850 rpm.

1st Attempt - timing measured at 8 BTDC
15mph 1930 rpm
CO2% 13.7 O2% 0.0 HC PPM (max 146) meas. 232 CO% (max 1.04) meas. 1.28 NO PPM (max 795) meas. 49
25mph 1919 rpm
CO2% 13.7 O2% 0.0 HC PPM (max 118) meas. 244 CO% (max. 1.32) meas. 1.23 NO PPM (max 855) meas. 42

The smog shop said it could be possibly be failing due to an issue with the O2 sensor or CAT.  I replaced the O2 sensor and re-checked everything including the timing and made a second attempt, same shop, with fresh Chevron 87 octane.

2nd Attempt - timing measured at 8 BTDC 
15mph 1946 rpm
CO2% 13.5 O2% 0.0 HC PPM meas. 188! (GP status)  CO% meas. 2.57 (GP status) NO PPM 565
25mph 1934 rpm
CO2% 13.6 O2% 0.0 HC PPM meas. 190! (GP status) CO% meas. 2.49 (GP status) NO PPM 375

So, it looks like the O2 sensor was a mistake, and my timing is an issue, but I would very much appreciate any feedback and help!!