Turboback Exhaust Install on 02-07 Subaru WRX:
Bone stock the WRX is one of the best performing entry level sports cars you can find, but there’s always room for improvement. Replacing the stock 2.25″ turboback exhaust and it’s 2 catalytic converters with a 3″ turboback exhaust, featuring one high flow cat, should allow the turbo to spool up easier and quicker for more low end grunt.
1.) Remove the heatshield. You’ll be amazed at the amount of bolts used to hold on this simple piece of metal. There are 5 on the left side (viewing from the front of the car), one on the back, and two on the right side. After you have all the bolts removed you’re going to need some keen geometry skills to get the heat shield out of the engine bay but once you do, the downpipe to turbo connection is easily available. Once the downpipe is exposed look for the bottom heatshield. It connects to the downpipe by one bolt.
3.) Disconnect the remaining hangers. It’s a good idea to use photos of the exhaust out of the car in order to point out where the hangers are in relation to the whole system. Install the new downpipe by lining up the turbo/downpipe bolts then securing the hangers. There are 2 hangers for the downpipe shown here. The front one bolts into the transmission. The second rests on a J bracket and is screwed in.