I have a 1994 Plymouth sundance with a 2.2. It failed utah emissions on NOx and Co help?
on the co’s it barly failed. and the car dose not have a egr valve what else could it be?
You most likely have two different issues to deal with.
CO is partially burned fuel, and is a sign of too much fuel for the air in the engine.
The causes can be —
1) Lazy or defective Oxygen sensor
2) MAP or MAF slightly out of range
3) Fuel pressure regulator out of range
4) Stuck open thermostat
5) Coolant temperature sensor out of range
6) Failing Catalytic Converter
The diagnostics involved require LOGICAL procedures in eliminating each of the causes, and there are tests to determine where the failure lies.
NOx is Oxides of Nitrogen, and is a result of very high cylinder temperatures combined with pressure (compression)
If there is NO EGR valve, then the manufacturer has chosen other methods of reducing the NOx, such as ignition timing modification, cam timing (some makes) temperature management, and PCM control of fuel, and of course the Catalytic converter.
Again, there are tests we can run to determine where the failure is.
Be very wary of anyone who looks at the failure report and says without testing anything, "ah, just throw a Cat on it" or "Just tune it up, it’ll pass".
It might do the trick, but at a possibly greater cost than actually testing the car to find the cause.
Your BEST option is to go to a Licensed REPUTABLE SMOG repair facility and pay them their diagnostic fee, and follow their recommendations. You CAN choose the shot in the dark method, ot the shotgun approach, but you will be less than satisfied, and probably some poorer for the experience.
Good Luck
make sure you don"t have vacuum leak.remove oxygen sensor and bench test it.next , replace the catalytic converter. this will pass your test
References :
You most likely have two different issues to deal with.
CO is partially burned fuel, and is a sign of too much fuel for the air in the engine.
The causes can be —
1) Lazy or defective Oxygen sensor
2) MAP or MAF slightly out of range
3) Fuel pressure regulator out of range
4) Stuck open thermostat
5) Coolant temperature sensor out of range
6) Failing Catalytic Converter
The diagnostics involved require LOGICAL procedures in eliminating each of the causes, and there are tests to determine where the failure lies.
NOx is Oxides of Nitrogen, and is a result of very high cylinder temperatures combined with pressure (compression)
If there is NO EGR valve, then the manufacturer has chosen other methods of reducing the NOx, such as ignition timing modification, cam timing (some makes) temperature management, and PCM control of fuel, and of course the Catalytic converter.
Again, there are tests we can run to determine where the failure is.
Be very wary of anyone who looks at the failure report and says without testing anything, "ah, just throw a Cat on it" or "Just tune it up, it’ll pass".
It might do the trick, but at a possibly greater cost than actually testing the car to find the cause.
Your BEST option is to go to a Licensed REPUTABLE SMOG repair facility and pay them their diagnostic fee, and follow their recommendations. You CAN choose the shot in the dark method, ot the shotgun approach, but you will be less than satisfied, and probably some poorer for the experience.
Good Luck
References :
ASE Tech
Licensed California Smog Tech