Happy friday! I have an 02 Shitsubishi Galant gtz V6 3L with 156,000 miles on it that has a code for p0300 and a code for each Bank running lean. I've changed the mass air flow sensor, the air intake filter, the fuel pump, spark plugs, wires, cap, rotor, and an alternator. I've even tried your vacuum leak test with the cigar in the pump. Unless I'm doing the vacuum leak test wrong I saw no leaks and I can't figure out what is causing my engine to run lean. It has a shutter at high speeds but other than that the car runs fine. Whenever I look up this issue in my other Galant groups or anywhere else on the internet everyone gives me a list of sensors to change. Could you tell me what your opinion is on the situation please?
Realize running Lane can be so many things often it can be vacuously on the intake manifold that no smoke test. It can even be a clogged fuel filter or a weak fuel of course it can also be fuel injectors that are clogged there's a lot of stuff that can do that and they're not that easy to test but start my pressure testing the fuel pump after changing the fuel filter
