Should i have to reset my ecu after fitting a magnex back box. my car doesn't seem to pull as much as it used to. the 2 cats are still on. Im getting the decat pipe in a week or so.

 

I have the cat back system for a MY01 & I wasn't aware that it needed an ECU reset, but my Dealer said it did, & did it for me at its service a week later. (This didn't solve my particular problem though- see 'ECU Reset Query' thread)