Hey guys, I just got an 05 WRX wagon, and had some questions about exhaust upgrades. I did search and read the FAQ's but nothing seemed to answer these specific questions. For now I want to keep the stock catback, maybe stock midpipe, maybe with an STI axle back, and want to replace the uppipe, and maybe the downpipe. I want to keep ONE working cat converter in the exhaust system.
For the uppipe, would it be best to gut the stock cat in the stock WRX uppipe, buy a stock catless STI uppipe, or buy and aftermarket catless uppipe?
Since I want to keep ONE working cat in the exhaust, and keep the stock WRX/STI catback, should I gut the stock cat in the stock WRX down pipe and keep the rear cat in the stock midpipe, buy an aftermaket catless downpipe and keep the stock rear cat in the stock midpipe, or buy an aftermarket downpipe WITH cat converter and remove the rear cat in the stock midpipe? (Which cat should I leave since I want to keep one there?)
Lastly, is the stock WRX and stock STI midpipe/rear section the exact same other than the axleback/muffler?