So I took my truck to a shop for other reasons. They said the fuel trim was really high +17-20%. I did have a bad/dead coil...they said that could be the cause, or probably a vacuum leak in the intake.


Well I got all plugs and coils replaced and the misfire is gone. My numbers are better but a little weird.

Bank 2: short term ft: +/-1-2 long term ft: +/- 1-2 as well.

However, bank 1: short term ft: (negative)-1-3 but my long term ft: +7-9.

1) is a long term fuel trim of +7-9 too high?

2) why is bank 1 long fuel trim +7-9 but bank 2 is almost perfect?

3) on bank 1, why is the short term fuel trim negative....but the long term is positive?