how can i tell if my car is running rich and how would i fix this and would it hurt my performance??

 

Running scan software should reveal if the PCM is compensating for a rich condition. Also is your gas mileage down? If your O2 sensors have 50K miles or more on them I'd replace them...the O2's are the sensors that measure the air/fuel ratio during part throttle driving to set your ideal mixture.

 

Running car without proper fuel mixture will definately affect performance and gas mileage. Running car with scanner hooked up will tell all, I love my scanmaster.