hellasboy

Everything else was fine (CO2, CO, NOx) but my hydrocarbon level was high... 3.9917 (limit is 2), which on the paperwork is 1823% greater than what is typical (0.22%). I passed 2 years ago w/ no problems.

I drive a '95 SC400 w/ 107k miles on it. I had new spark plugs and fuel filter done at 96k miles. I put in a new air filter a couple of months ago. anything that i should be looking for?

thanks

steviej

iTrader: (1)

was the cat. hot when it was tested?

steviej

hellasboy

I was driving for about an hour before but they make you turn off your car when you get to the emissions testing. it was running for about 10 minutes before they did the actual test. it passed 2 years ago and my car was the same except without the new spark plugs.

My CO2, CO, and NOx levels were fine so I don't think it's something with the cat.

SeattleGS400

iTrader: (1)

Here's some info to help you figure out why your HC exhaust gases are so high--see the PDF file.

From the file (troubleshoot in this order--assuming normal CO levels):

1. O2 sensor operation (1st thing to check)

2. Faulty ignitions:
*Incorrect timing
*Fouled, shorted or improperly gapped plugs

3. Incorrect valve clearance

4. Leaky intake and exhaust (next highest possiblity)

5. Leaky cylinder

Hope you get it to normal levels again.