As I am looking at a replacement up pipe for my 05 WRX, I learn that an 06-07 stocker would eliminate the cat, which is half my goal. The other half is to make more power.
Has anyone done the work to see if there is a difference in power from a stock catless to a performance (Cobb, Perrin, Grimmspeed) up pipe when going from a catted 05 stocker?
If no, then I'd be hard pressed to beat the manufacturer design and low ebay price (65.00) of the 06-07.
Thank you for the input.