One thing I wouldn't try doing is removing the resonator and replacing with a straight pipe. I run a dual exhaust with Magnaflows out back. When I had a straight pipe out back, I lost a lot of throttle response. Also car was just plain too loud. Sounds weird about the throttle response, but I think that the car needs some sort of backpressure. My Contour is a 97, GL Duratec with at ATX. 192K