check engine light is on.....car.......runs good!!
 

question for you guys, ever since i removed my cat my check engine like came on immediatly and its been on ever since, now my quetion is , is this bad for my car in anyway? .......why is water wet? ......why does fire burn?

Re:check engine light is on.....car.......runs good!!
 

The light is on because the rear o2 is ouputting the same voltage as the front indicating to the ecm that the convertor is ineffective, or gone in this case. That code will not send the ecm into a fail safe mode and the car will run fine.