I have had aftermarket exhaust on my car for about 7000 miles now and my check engine light keeps coming on. I have a Bassani x with cats, would this still set the light off? I figured the cats wouldn't make a difference. Resetting the light by unplugging the battery only lasts for a few miles, then its back on again. Ford won't touch it becuase of the aftermarket exhaust. Anyone have any suggestion?