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

77,735

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

  • smog 2 answers

    I have a 99 s10 can I take the exhaust from a 2000 s10 blazer and use it ?

    Maintenance & Repair

  • Can I drop my 1994 GMC Jimmy engine into a 2004 Envoy? 4 answers

    My 1994 GMC JImmy was t-boned and insurance wants to total it out and pay out very little. The engine is still very solid. It has been our cabin car for the last 10 years. Stored winters and only...

    1994 GMC Jimmy 4 Dr SLE SUV

    -

    Maintenance & Repair

  • 1994 gmc suburban 1 answer

    My truck starting but not run, I check gas system its in good condition, please help me

    1994 GMC Suburban K1500 4WD

    -

    Maintenance & Repair

  • 5.7 l gmc 1500 1994 1 answer

    What heads could i upgrade my 5.7l truck

    1994 GMC Sierra 1500 C1500 SLT Extended Cab SB

    -

    Maintenance & Repair

  • what kind of transmission is in my 1994 GMC 1500 4x4 6.5 diesel 3 answers

    what kind of transmission is in my 1994 GMC 1500 4x4 6.5 diesel

    1994 GMC Sierra 1500

    -

    General

Shortcuts

Search Maintenance & Repair Questions

Maintenance & Repair Experts

#1 Tom Demyan
Tom Demyan
Reputation 149,960
#2 FordNut
FordNut
Reputation 102,920
#3 dandyoun
dandyoun
Reputation 83,990
View All