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Old 04-17-2022, 06:17 PM
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workingonit workingonit is offline
Join Date: May 2021
Location: DFW Texas
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reset fuel trims; lasted about 60 miles or about an hour

I accidently reset my fuel trims, by unplugging the MAF sensor repeatedly several times while it was running. The very high long term fuel trims went to zero, and the short terms stayed low while idling. Well, I finally found out how I accidently reset my fuel was by repeatedly unplugging and re-plugging the MAF sensor
Originally Posted by wamcdonald
With car running disconnect the MAF sensor wait a few seconds and reconnect it, that's it. The car may stall but just re-start and you may through a MAF code but this gets the values back to zero.
I hate mysteries, so that's reassuring that it's been done before, with the same results.

That was over a week ago, and today I took the X5 on a >100 mile trip, just to see how long/how many miles the "reset" fuel trims were good for; I refer to this previous post, where I pondered this question:

Now I know...if I haven't solved the SES light problem, as triggered by P0171, P0174, and P0313 codes (where the fuel trims are very high) before inspection time in October, I might have as long as 60 miles and/or about an hour of drive time before the fuel trims go sky-high again, and set off the SES light (I saw and marked the time and mileage as the SES came on).

had suggested the reset adaptations may be able to gain a week's grace period, as a grace period at inspection time;
Originally Posted by andrewwynn
reset adaptations may get you a week or more no error code to get an inspection pass while working out the problem
what adaptations he meant, I don't know, but while I'm trying just about anything to resolve the problem (visual inspections, smoke test(s), carb cleaner spray test, MAF cleaned and tested, O2 sensor functions tested OK, etc.), with no problem source found, I'm willing to cheat a bit to pass the test.

My X5 is just under 21 years old, runs perfectly fine, no hint of a smelly or rich exhaust (to my senses), and though the scan tool says that there is an infrequent lean misfire, my "seat of the pants feel for the car I'm in" tells me no such thing. It runs smooth as silk at any speed, from a 700 rpm idle to 80 mph.

Anyone care to venture a new approach? or will I end up praying to get a one hour or 60 mile window of opportunity, where my X5 can pass inspection? If it was just 4 years older....
'01 BMW X5-E53 3.0i (born 7/13/01)
topas-blau, Leder-Montana grau,
my new favorite project car

Plus four GM vehicles: 2 Daily Drivers, and 2 modified trucks (for hauling & camping):
3 Chevys:
'09 HHR Panel LS 2.2L,
'08 Cobalt Coupe LS 2.2L,
'04 Silverado 2500HD WT Reg. Cab
+ a '98 GMC Sierra 1500 Ext. Cab

- and 20 others, now gone, that I've had over the last 58 years (not counting the stillborn "1965 ChevyII altered/gasser project")
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