I have a 2012 Golf Base Automatic with the 2.5 motor. I seem to be getting pretty lousy gas mileage. Around 19 in the city. I've changed the plugs, coil packs and air filter with no improvement in MPG. OBDEleven detected a dirty throttle body so I cleaned that. Maybe has more power but did not help with MPG. It runs fine and the idle seems pretty smooth. I'm thinking maybe try the upstream O2 sensor? Anyone ever change that and see a boost in MPG? It isn't throwing any codes but I assume it could still not be performing well. Car has 115k. I bought it used. I see no evidence that the O2 sensor has ever been changed in the service history. Suggestions?
Thanks!
Thanks!