QuestionQUESTION: Hi, I would have asked TIM this because I know he is heavily into the Geo thing, but I was wondering if you can help me figure out why my car failed the emissions test here in Houston, Texas. It read at over 2k when the standard is a little over 1k.
The car is in wonderful shape, and drives fine, however I just had a valve cover gasket swapped and the tech had to remove some wires due to a tight fit, but it looked to me like he replaced them all.
I was wondering if this was a Cat problem, or possibly a EGR assuming this car even has one ( I have no idea where it would be located )
Please give me an email any time for more information, I am not sure what you need to know. THANKS so much! :)
~Vance
ANSWER: I woud need to know the values of the emission readouts, you should have a printout, I need all three readings and the state's limts on them. Is the check engine light on and if so what are the trouble codes?
---------- FOLLOW-UP ----------
QUESTION: No Check Engine Light
----------------25MPH-------------
Pollutant----Pass---Mine---Result-
HC(PPM)------147----141-----Pass--
CO(%)----------.82----.47-----Pass--
NOx(PPM)-----1072---2056----Fail--
----------------15MPH-------------
Pollutant----Pass---Mine---Result-
HC(PPM)------152----153-----Fail--
CO(%)----------.85----.48-----Pass--
NOx(PPM)-----1186---2068----Fail--
AnswerThe main problem is that the NOx readings are too high, the most common cause for this is that the engine timing is off, has this been checked? Another reason for high nox is that the engine is running a little hotter than normal, so check it for that. It may be as simple as replacing the thermostat to get the engine to run a little cooler, as engine temperature goes up so do the nox readings, this is why egr systems were installed so that the exhaust gases are cooled and then recirculated to cool the inside of the combustion chambers.
