OK, got the car back last night. Seat-of-pants dyno indicates an improvement in power. Comptech claims 12-18 additional horsepower with headers and stock exhaust, 20-25 more with headers and cat-back. I am going to do some G-Tech Pro trials to see what kind of numbers I come up with. No problems with O2 sensors, seems to rev faster, sounds meaner, not much louder at idle or low rpms, noticibly louder at WOT,
definitely feels quicker- maybe .5 sec 0-60.
BTW- my mechanic was impressed with the quality and light weight of the parts and the ease of the installation. Overall, I would recommend CT headers and exhaust.