My 93 Jimmy failed emissions terribly. Here are the results:

HC (PPM)
Limit: 160
Emissions: 628
FAIL

CO (%)
Limit: 3.01
Emissions: 11.68
FAIL

NOx (PPM)
Limit: 3907
Emissions: 0
Pass Although it passed, something is wrong, it shouldnt have been 0.


So, what should I begin to do to make this rust bucket pass emission tests?

Let's start fro the beginning, is the engine completely tuned up?

what do you exactly mean tuned up.

we changed oil, air filter, oil filter, stuff like that?

what do you exactly mean tuned up.

we changed oil, air filter, oil filter, stuff like that?

No....

Plugs gapped properly
Wires
Cap & Rotor
Base Timing set with timing wire disconnected from PCM under the glove compartment
EGR Cleaned
PCV Valve replaced
Fuel injector cleaner run through it.

If none of these haven't been done for a while, you can see where your failure is coming from.

wow thanks blazee your awesome you to blazerlt

You're welcome :)