2.2 litre 99 legacy 5spd. 2.5 inch exhaust highflow cat. After market unequal length headers
The car is losing power at 3500-4000 rpms and right off the line. Throwing codes for an 02 sensor and the system running lean.
Has trouble starting (stalls out very often right after it starts)
Has a rough idle, generally runs shitty and has very little power.
Replaced the 02 sensor and the problem ensued.
Noticed a hissing coming from the engine and a vacuum leak seemed very probable. Tried doing a cigar smoke test through the PCV hose and only got smoke out of air box, so I couldn't find a vacuum leak.
New MAF sensor, clean PCV valve, plugs/wires good, clean gas.