P1093 SEARCH FOR A FIX CONTINUES...

[mendes9]

I've don fuel pressure tests perfect at 50PSI, i've swapped downstream sensors (replaced both on bank 2). I've smoked tested from intake, and from tail pipe no leaks (smoke test from tail pipe does have small leak but it's after downstream O2 sensor. MAF doesn't make sense why wouldn't it effect both? Have to keep testing. Question, when you say reset the MAF, what do you mean exactly?

[workingonit]

As stated above, I've unplugged the MAF sensor many times in the past, when the cumulative values (LTFT + STFT, for each bank) would go past 20 (maybe 25, it's been awhile, so I forget which), and prevent the SES/CEL from happening. I didn't want to go into limp mode, especially if I was far out of town.

That's also the reason I had 3 MAF sensors with me for 3.5 years, and would swap in a fresh, clean one after reset. That worked OK, if not perfect, until my oreiginal OEM Siemens MAF went nuts and instantly set codes, & SES, and caused driveability problems once, out of town, and I had to quickly exit the highway to insatll a backup.

That was just prior to X5chemist sending me his spare Siemens MAF, which I'm testing (if ever so slowly). So far, the X is seeming to relearn, keeping the fuel trim number reasonable, but still on the lean side.