cant smog my 1994 gmc truck

Asked by Nov 12, 2014 at 05:47 PM

Question type: Maintenance & Repair

I have a 1994 gmc 1500 sl with a 4.3 and 5 speed manuel trans it has 333942 miles but
runs like a champ I went to smog it and it failed in nox at 15mph it was 650 max is 500 at
25 mph it was 1091 max is 754  my cat conv is only 4 years old what to do louie

1 Answer

92,655

That is a lot of mileage for a 4.3, you must take care of it, have you had the codes checked? There could be some stored in memory that will steer you in the right direction, could be an O2 sensor just out of specs but not open or shorted so it won't turn on the check engine light. Might do a compression test just to make sure the compression is good and not too low.

Your Answer

Add photo

Related Questions

Shortcuts

Search Maintenance & Repair Questions

Maintenance & Repair Experts

#1 Tom Demyan
Tom Demyan
Reputation 168,630
#2 dandyoun
dandyoun
Reputation 91,510
#3 tenspeed
tenspeed
Reputation 73,850
View All

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.