I had Borla headers and a Borla catback installed on my car and drove it for over 20thousand miles without the check engine light ever going on. A lot of people seem to experience a CEL with aftermarket headers, so I figured my ECU wasn't as picky as many others are.
Then I installed a random tech high flow catalytic converter. A couple hundred miles later the CEL came on; the classic P0420; catalytic converter low efficiency. This CEL will always come on after a long period of driving with cruise control or at part throttle.
Bought the GP Moto CEL fix, installed it, reflashed the ECU, and the CEL came on again after maybe 30 miles of cruising on the highway.
Conclusion; don't waste your money. Does anyone know of a CEL fix that actually works?
Here is what the GP Moto looks like. All mechanical CEL fixes are essentially the same thing; they place the rear O2 sensor further away from the exhaust gas flow.