Kai....if ur out there....

I just spoke with the previous owner...I guess the ecu has a Mugen chip in it, but he says it's programmed to the engine. He said that maybe if I swapped the cat converter (catback/ractive exhaust) back to a stock cat converter that might help the cars preformance....what do you think? Will it stop the popping/backfiring and the strong fuel smell?

Thanks again for your advice

~Kiersten