First off im going with a 2.5" exhaust.

Im getting the LSJ Pacesetter header. Should I bother with going with a 3" downpipe or will a 2.5" suffice?

Next up is the cat. Ive heard mixed reviews of the Magnaflow cats. I was just going to go with the typical ceramic high flow cat but now im reading about the smaller spun metal cats and such as well.

Since I have emissions testing I cannot have a code for the cat. (I know I can space it out or use a j-pipe)

But I want to know whats the best option for cats, or should I just go with the typical Magnaflow ceramic and just expect to change it every couple years.


**IM concerned about knock mostly because I swear ive read on here that a 2.5" downpipe will tend to make knock easier.