Hey, sorry for such a late reply! I have both the top speed pro 1 delete pipe and the exhaust. The CEL will remain off unless you tamper with the headers. If you look under your car, there is no sensor at all that connects to the secondary cat. For the droning, I personally do not mind but to some individuals who sit in my car, it was extremely annoying. It just depends on your preference.

Hi there, so with the CAT bypass/delete pipes, the "Check Engine" light does not come on, right? Because O2 sensors are only in the pre-CATs. Right? Got the TSPro-1 exhaust and have the typical 2800-3000RPM drone so was looking at the CAT delete pipes.

Thanks!