umm damn lol ok we got a performance upgrade (cobb acessport) the guy traveled over here from the states and did it for us while he was doing work on an Sti a friend of ours owns. After he installed it he went in and did the maps for us. I really don't know much about this kind of thing

Basically it backfires when I'm shifitng... Thats pretty much the only upgrade, we were supposed to get a new exhaust at the same time but it didn't come in on time. If Im correct there is no catback in the exhaust...I really don't know much about this kind of thing, sorry if im not answering your questions correctly

Its an '02 WRX Turbo charge ...