Originally Posted by dubster99
I think the same thing happened with my car the last time I smogged it. Everything was way below max except HC, which was right near the max. HC's come from unburned gas. The cat is supposed to turn the hydrocarbons into CO2 and water. Maybe you're running a little on the rich side, or the cat isn't completely doing the job?
I made sure the car was nice and hot coming off the freeway but I had to wait about 30min before the actual testing began. When I got the car back the oil temp was below 200F so it wasn't fully warm. I hope it's not my cats, I have 4 of them and they are $$$$$.
Not sure why the car would run rich unless it went into warmup mode. But that's only suppose to happen on the first cold start of the day and for the first 10mins.
Might be time for another dyno run to get my O2 level checked :rick: