Muffler delete- can cause issues with backpressure and the car is NA.
Yes muffler deletes have been proven to lose power in our cars. so i wouldnt do it.
Cat delete- can cause issues when the car starts heating up.
2nd cats can be deleted with out any issues.
Res Delete-code issues?!
Res delete will not cause any code issues.
If you wanted more sound ide delete the 2ndary cats and see how u like it.
cause in my option when i deleted the RES i noticed jack poo in sound.
I got a amazing exhaust guy who dose all my work for cheap.