Emissions Failure
Emissions Failure
I had my emissions tested today. I failed on the HC and CO levels. In Missouri the acceptable HC level is .8000 grams/mile, and mine was 2.2053. The acceptable CO level is 15.0000 grams/mile, and mine was 93.1990. The NOx level was .9776 - about half of the max acceptable level. I was wondering if these numbers ppint to anything in particular. The O2 sensor doesn't seem to be putting out any volts at all - about .001-.004. The volts don't change much as the car warms and gets revved either. Could the O2 sensor alone cause the numbers I have and if not, what would be the next thing to check out?
O2 will play a large part in those numbers you are definitly running supper rich, and if your O2 numbers are very accurate it is stuck on the lean side. the O2 should fluctuate from 0.0v to 1.0v more between .175v and .8v if it is sending a constant lean signal to the ecm the ecm will lengthen the injector pulse cuasing it to run much richer then it should. Replace the o2 and get it retested.
Be warned though in many cases when you fix a high CO problem the NOx will increase in some cases to a failing point if the EGR is not functioning. High CO means it has alot of fuel going in the cyl and this over abundant amount of fuel will help cool the cyl a bit and with out heat NOx can not form.
Other things that can cause high CO is coolant temp sensor and MAF but fix what you know is wrong before you tackle something else as the failure.
I wouldnt worry about the HC's at this point as that represents raw fuel and with the numbers on your CO it indicates it is running very rich so thats where the HC's are likley coming from.
Be warned though in many cases when you fix a high CO problem the NOx will increase in some cases to a failing point if the EGR is not functioning. High CO means it has alot of fuel going in the cyl and this over abundant amount of fuel will help cool the cyl a bit and with out heat NOx can not form.
Other things that can cause high CO is coolant temp sensor and MAF but fix what you know is wrong before you tackle something else as the failure.
I wouldnt worry about the HC's at this point as that represents raw fuel and with the numbers on your CO it indicates it is running very rich so thats where the HC's are likley coming from.