Would replacing my old, crappy catalytic converter (which the car was tuned for) with a high-flow cat warrant a highly recommended retuning? or would it be fine to leave it and retune it after another modification? (intercooler, etc.) just a quick question, thanks! [p.s. this is with regards to a Power FC on the car]

 

I doubt that you would need a re-tune. Just keep an eye on the boost gauge for a while. It will go up, especially if the old cat was a little clogged.

 

whats your car already tuned for? going from a stock cat to a hi flow wont change too much that you would need a re-tune just from that, and neither would an IC... but keep an eye on your boost.