I know this is an old thread but I am having an odd issue and want to rule my MAF out as a cause. I have a 02 E55 and I am getting -18% fuel trims (less then 1% difference left to right) with my new MAF module.

I have post my original question in this thread but I am not getting any answers

Fuel trim and fuel pressure questions/problems

Thanks

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Eraser-X
06 R350 with sport package
02 E55 Black on Black with most options
91 Range Rover GDE
8X 280TE
53 356 Cab