Badwolf
New member
I have a 1990 3.0 5 speed. Passed emissions 2 years ago.
Failed emissions this time. Way over on CO (46 - limit is 20) and slightly over on NOX and HC.
Tried a couple of quarts of alcohol, set timing just right, and cleaned the heck out of the throttle body - didn't really do anything - results WENT UP slightly (go figure).
Changed the catalytic converter - same result. Got a print out of the driving cycle, and the smog GOES WAY UP during acceleration (well, obviously) but almost seemed like the motor is running too rich - checked the cold start injector (figured it may be it was continuing to shoot in fuel when warm). It's working fine.
Plugs and wires are okay, although I'm probably due for plugs, rotors, cap, and wires. The idle is running high (1050-1100 rpm, usually, which lead us to believe maybe the cold start injector was staying open).
Our next idea is the O2 sensor.
I mean, what the hell else could it be? The check engine light IS NOT on, and the engine is throwing NO CODES.
I'm effing baffled.
Thanks in advance.
- Paul in AZ
Failed emissions this time. Way over on CO (46 - limit is 20) and slightly over on NOX and HC.
Tried a couple of quarts of alcohol, set timing just right, and cleaned the heck out of the throttle body - didn't really do anything - results WENT UP slightly (go figure).
Changed the catalytic converter - same result. Got a print out of the driving cycle, and the smog GOES WAY UP during acceleration (well, obviously) but almost seemed like the motor is running too rich - checked the cold start injector (figured it may be it was continuing to shoot in fuel when warm). It's working fine.
Plugs and wires are okay, although I'm probably due for plugs, rotors, cap, and wires. The idle is running high (1050-1100 rpm, usually, which lead us to believe maybe the cold start injector was staying open).
Our next idea is the O2 sensor.
I mean, what the hell else could it be? The check engine light IS NOT on, and the engine is throwing NO CODES.
I'm effing baffled.
Thanks in advance.
- Paul in AZ