andresinibus

not sure if this is the right place for this tread but here it goes i got a 350 engine with q-jet on it went for emissions and it fail the HC and CO. HC limit is 2.40 and im pushing 5.47 also CO is 20.00 and im pushing 80.22 NOX are ok at 2.26 while the limit is 3.50. i did a spark plug and wire swap also swapped the egr valve CO went down to 59.28 but no other improvement air pump and related parts are not in the car right now also the cat was swapped once i can tell but car was sitting for a couple years BTW it had a hole in the side where the air line hooks up just welded it shut (i know getto fixing) any ideas suggestions appreciated thanks

five7kid

Is your SES light coming on? If it is, have you checked for codes?

High HC is due to unburned or partially burned fuel. Basically a misfire. Did you do the cap & rotor while you were at it? You might also want to do a compression check to make sure you don't have low compression or leaking valves (especially exhaust valves).

High CO is a rich air/fuel mixture. If this is a computer q-jet, the O2 sensor can be weak, telling the computer to richen the mixture when it shouldn't be, without setting a trouble code. Also, if the computer isn't going into closed loop, it will use preset values which typically are for cold operation, and will be too rich.

The EGR valve is for NOx, which was in tolerance. Changing that didn't affect your results. Besides, a rich mixture will tend to lower NOx.

A bad cat will raise both HC and CO. Functioning A.I.R. will lower both. Since your cat doesn't have the A.I.R. tube, I would recommend reinstalling the A.I.R., and replacing the cat with one with the tube.

kwp289

yeah I failed for the same things. First I got a tune-up and it didint really help. So then I put on a new hi performance cat and new O2 sensor,then I passed when the engine was cold.

andresinibus

sorry it took me this long to reply guys i got a new cat installed im replacing my O2 sensor also i got all the parts for the AIR system i will install later maybe this weekend as far as the codes i haven't pulled them yet maybe later today after work what i noticed is the check engine light coming on but only during deceleration once i step on it it turns off again. the egr i replaced cuz it didn't work and also i had the evil code 32 ill check for new ones today. I don't know if it has anything to do with the deceleration thing or if it affects somehow that i just swapped from auto to standard and changed my speedo to a 145 from an 85 (on that note and a little out of subject was i supposed to do something with the speedometer since now i have a standard tranny and 145 speedo in the highway it only says im doing 45 when im going like 70 or so) thanks guys

andresinibus

ok codes are 24, 32, and 44. 32 again even do i swapped the egr valve. code 24 is for the speed sensor probably activated cuz it shows im doing 45 when im really doing 70. and 44 is a lean exhaust any input or ideas?

drknow90rs_ss@y

Replacing the o2 sensor should fix the code 44. If you still get the code, check the wiring for the o2 sensor. The A.I.R. system is really key to getting through emissions in az. I would install the parts and try again.

andresinibus

thanks man thats what i plan on doing i got most of the stuff that i need now i just need to replace it. O2 i bought new so that should fix it and the stupid code 32 i dont know y till shows

andresinibus

well i just want to tank everyone for their suggestions i got the air system in place along with the O2 sensor new cat and all for nothing we are moving to TX at the end of October so im not even gonna bother going for emissions no more im just gonna get a 3 month permit $19 and i know ill pass in TX since i used to live over there and i got all that stuff on now ill let you guys know how it turns out do.

five7kid

For carb'd engines, Code 32 is "Fault in barometric pressure sensor circuit". You'll want to fix that regardless of emissions results (and it may be causing your failures, along with the O2 sensor).