My '95 failed the CO% test for IM.
Idle was 0.04, but 2500rpm reading was 0.60, max allowed is 0.50.
Any advice as to what might be the cause?

Gordo

 

Are you sure the car was fully warmed up? I usually go for at least a 30 minute highway drive before going into the testing place. And they also tell you not to turn off the car (if you've in line - let it idle) before the test.

 

You might be on to something there.
No the car was not very warm, and it did sit for quite a while prior to the test.

I have not run it hard for quite awhile, due to icy roads. Think it might help to bump it against the rev limiter a few times?

From the little bit of research I did on Rennlist, it looks like a warm car might show HIGHER CO%....though I may have mis-interpreted all the tech talk. Your thoughts?

As I noted, CO was way low at idle, but over by 0.1 at 2500 revs....do these cars tend to just skate under the max?

Gordo

 

PASSED!
Thanks for the advice mikeandnancy, getting engine hot did the trick.
CO on failed test was 0.60, passed at 0.39.