Yea my wheels arent much bigger. theyre 255/55/17. But yea it still really puts you back in your seat. No i have no error codes. How would i test to see if my cat is plugged? And yea im aware that its old and prob isnt putting out the same horsepower but i wouldnt think it would be that signifigant. My friend just sits in the car with me and uses his stopwatch on his cell phone to see. Not the most accurate i know but it deffenatly wont be 2 seconds off. Thanks for the quick reply guys.