OK so...had and exaust leak, took it in and they put from the manifold back to the muffler including the cat, a couple days later the engine light came on, cyl 1 and 4 misfire, I have never changed the plugs so I did that, ran better, then on idle light comes on Misfire code cyl #4, found bad intake gasket, now it runs a lot better, but it still has a slight mis on idle and if it idles too long the light comes on cyl #4 misfire. changed all 4 coils and all 4 injectors, LTFT is at -17.2 on idle or light throttle when driving, if I step on it it seems to clear up an drive fine, my gas mileage has recovered after the intake change, it almost sounds like there is some kind of leak near cyl 4. compression test is cyl 1-2 135 psi dry and cyl 3-4 150 psi dry, all cylinders held 100 psi on leak down, I'm tired of changing parts. so is it MAF or an O2 or WHAT!!!!! lol TIA
2009 Vibe 1.8 229,000kms