Hi

I am new to this so just getting hang of it. I have Volvo v50 09 2.0 diesel. getting a custom dual straight through exhaust but wanted to know should I leave cat in or de cat it.

I have heard that some cars require the back pressure so by removing the cat I could in fact lose power.

Any help greatly appreciated

P.s
just started doing a complete strip out on a crashed v50 so any questions on anything jus ask.