Fuel trim diagnostic puzzle for you

[jb92563]

I'm the one with the how-diagnose-resolve-engine-issues-using-durametric

What device are you taking the readings with?

The LTFT are a bit high meaning they are adding fuel to compensate for a lean condition. Perhaps the MAF is not right on spec, or a small air leak at the intake.

Mine are around +5 and I have read that up to 10 is not abnormally high. Over 25 with throw a fault code.

You MAF is reading fine.

The concern is the LTFT spikes on one bank. Either a loose connection to an O2 sensor, failing O2 sensor or interference in your signal reception for your reading device.

I also have signal spikes and figure its just data capture errors or interference.

Could be loose connections though but I replaced the front O2 sensors and a multitude of other things that had no impact on my signal spikes.

Since you are only getting these spikes on one bank by readings and the fault code confirms it on one side only, I would check the 2 bank2 O2 sensors.

Try swapping the O2 sensors from bank1 to bank2 to see if the problem then switches to bank1, which would confirm bad sensors.

If Bank2 still acts up then I would look for bank 2 header or intake leaks.