Re: Don's 08 STI. STI Hatchback/Wagon or bust!
Fixing vacuum leaks is a very tedious process. I had a/f learning 1 as high as 20%. I proceeded to clamp down all the vacuum ports on the intake manifold and found another leak at the vacuum hose to the bypass valve. Right now, it's at 14%, plugging up the leak at the bypass valve dropped it down to around 8%. So many vacuum leaks!
Last edited by STIGR-Wagon-Dad; 07-21-15 at 12:33 PM.