I took my car to the stealership for diagnostics. They told me the MAF voltage was off and was the wrong part number for my car and could not go any further without replacing it for $400+ so I went and got it stopped by Autozone on the way home and bought a remanufactured MAF. Needless to say my fuel trim on bank 1 is still 7-9% lower than bank 2.
My upper O2 sensors are switching well (even the stealearship said so). The injectors are holding pressure well. What else could cause the bank one fuel trims to be so much lower. When I switched the two upper O2 sensors they were chalked as if the engine is really running lean.
What's really odd is my brother has a 24v 2000 Taurus with the same code P0172.
