Thank you guys for trying to help everyone. Ok, I have a 2002 nissan altima (2.5 4 cylinder) and the check engine light recently came on. I also noticed that I was burning up ALOT of fuel and also only one of my exhaust pipes was blowing air out of it. The other was was blowing out air at a minimal. Nissan changed the cat converter but I still noticed that the air is still only coming out of one exhaust pipe much more than the other. Did nissan really change the cat converter? Or is this even a problem. Thanks.
The check engine light is off now. It does feel a little better though. But I was starting to wonder if the guys at the dealership just did something to make the light go off or if they actually put in a new cat converter.