Failed emissions test in Illinois.Car was put on dynamo. These were the readings;HC 2.32; CO 22.4;CO2 N/A ;NOX N/A .Any ideas as to what is the cause? thank you

You can get the codes from the computer. See if its lean or rich. If lean look for leaks in the air duct going from the MAF to the thottle body. If rich test the O2 sensor and the fuel pressure regulator (easy to install). If all your emissions are high replace the catalytic convertor with an aftermarket one especially if its 5+ years old. Aftermarket cats last 2 years. I just failed my emmisions 3 weeks ago with all readings high. After a new cat it passed with very little readings.

The MAF and 02 sensor can be checked with a voltmeter/multimeter.

I beleive that your car might have the self diagnostic computer. If you need help with the codes please post. They are in the Bentley and Haynes <--(crap) manual.






Chris

It could be a lot of things. A weak Cat, a slow o2 sensor. If it was really really rich I would say a fuel pressure regulator or coolant temp sensor.

"If it was really really rich" I'd have to say that 22.4% qualifies as really really rich. No amount of catalytic converter is going to help you here. You need to start with the basics on this thing. The O2 sensor and cat may very well be done in it but you won't know until you fix the grossly over rich condition that exists. Start with a simple fuel pressure check and see where that is, at 22%+ a stuck fuel pressure reg is entirely possible. Then check yor MAF for proper operation. I'll bet that your MAF is toast and if it is make sure you check/replace the pre-heat thermostat when you put in the new MAF. Also make sure that you do not have any melting down harness issues as well, I have seen a few with the disintegrating harness that has taken the MAF or other components out with it. Bad things happen when all of your wires short together. Lastly, it is called a dynomometer or a dyno for short, a dynamo is something completely different. Thank you for letting us know that it was on a dyno though and for providing all of the numbers. It is tough enough to give you an idea of what is wrong with your car with the numbers and the correct information. Did they do a two speed test and you failed at both high and low speed?

Mark

what is a MAF?

Sorry about that Fireman, it is the Mass Air Flow sensor. It is attached to the airbox where your airfilter goes and it measures the mass and density of the air coming into the engine. Between the MAF and the O2 sensor those two components pretty much determine the engine load and fuel mixture settings. There are other factors but those are the two big ones right there.

Mark