FYI. I installed Cat deletes a few months ago. I read that installing two spark plug fowlers between the O2 sensors and the exhaust would trick the computer. It does not trick the computer. I even tried a third spark plug fowler. The CEL comes on after about 20 miles of driving. The good news is that the car runs fine. I still haven't been able to get the car to the drag strip to determine if it's really making more power.