Originally Posted by DOHCGS_92

Couldnt this be a contribution of backpressure ?.. I know my 00 Gt eclipse had a rowdy backfire when shifting gears after I added a Greddy EVO my first week of owning the vehicle from 0miles(Brand New, No mods or motor problems).. Just a thought, not saying this is your solution, But it may not be anything to worry your self over.