Failed emissions

[mfitz725]

My 94 Exp failed emissions on nox. I am getting codes 172 and 176, heated sensor indicates lean condition on left and right sides. Lean fuel mixture can be a cause of nox failure according to the info from Georgia Clean Air Force. Does anyone have any suggestions for correcting the problem.

 

[Rhett]

Those are oxygen sensor codes, and a lean condition on these trucks is often worn oxygen sensors.

Your truck, a 94 like mine, should have two O2S, one on each exhaust header if I recall correctly.

Some states allow you to license your vehicle as an antique or historic plate car, and are exempt from emissions. Maybe Georgia has this, and you can look into it when the time comes. In MO it is a 25 year old vehicle or older, so ... we're getting close here with my truck, no inspections, no emissions.

 

[natenkiki2004]

If you can believe the O2 sensors then look for a vacuum leak, that's probably the easiest and most common issue.