I have a totally stock 94LT1 swapped into a 95 base camaro body. Motor has about 100,000 miles and passed Maryland emissions 2yrs ago. This time, I failed HC. I logged a couple minutes w/Datamaster and wondered if someone could look at it for me ? I have no idea what its telling me, but am willing/eager to learn. I have Tunercats, but only used it to put the file in the PCM when I did the motor swap originally. Could I email this to someone to look at ?

Thanks

 

should I post this in "LT1 Engine Tech" ?

 

What were the exact test results, and the pass/fail limits for HC, CO and NOx?

 

HC limit 0.900 GPM result 1.629 GPM
CO " 20.0 " 9.2169
NOx " 2.1 " 2.0959

As you can see, failed HC, and almost NOx. I have not touched this motor since I put it in w/80,000 on it. At that time, I put new plugs & wires on and a new cat and Hooker cat-back. I've had no issues with it. What do ya think ?

Thanks for the reply

 

With both HC and NOx being high, I'd suspect the cat.

 

hmmm...ok, any way to get a better feel that its pointing to the cat ?

 

HC usually means you can change your oil and filter and plugs to pass in the retest. My emission guy used to make me run up and down the highway a few minutes and come right back for my retest. It always passed after I ran it hard.

When you go to get an emission test make sure your car has been running a minimum of 30 minutes. It takes almost that long for your cat conv to work properly. So if there is a couple people in front of you leave your car running. You stand a much higher chance of passing.

So did you pass now?

 

good call ... put on a new one and passed !
Thanks for your help.