I purchased a 2015 WRX about a year back and recently I had begun to suspect a turbo/exhaust leak as I felt slightly sluggish acceleration and a lack of response from my turbo. Soon after my check engine light came on and the computer was giving a code of “P420” catalyst system below threshold. In bring it to the dealer for my regularly scheduled oil replacements (coincidental) I asked the tech to give it a once over and sure enough… there is a decent sized leak in the mid-pipe from a poor weld. The tech showed me a picture on his phone and it was obviously not a factory weld. I wish I had the foresight to have him send me the pic. The car had been in one minor accident before I purchased it so I am assuming someone did a slap-dash job of repairing it. I’m assuming some recent jolt did it in. The system is otherwise stock.
In lieu of paying north of $3,000 for Subaru to replace just the mid pipe I would rather buy an aftermarket kit and install it myself. Both as a cost cutting measure and to become more familiar with the mechanics of my car. I have attached a picture of the parts list supplied to me for just the mid-pipe assembly below. However, going aftermarket I would like to replace from the damage, back. Which I am assuming means I need more than just a typical Cat-back system. In this case is it actually a Turbo-back system system I need? Or is it a Cat-back + a catted J-pipe? Are those in-fact the same thing and I am just a dummy?
Overall if I can keep the damage to about $2,000 and get a small performance boost I would consider it a win. I suspect something may still be funny with the turbo but as this is the obvious issue at the moment I think it make sense to solve this and see if it solves the other symptoms before moving on to hunting for a turbo leak. Any advice, suggestions, best practices would be GREATLY appreciated.
Thanks in Advance for your time!