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Discussion Starter #1
So this code comes up when checking immediately after clearing the fault but the check engine light doesn’t come on. Maybe the pcm will trigger the CEL after so many miles?

I’ve replaced with a MAF with a known good unit and I’m reading MAF values with a OBD2 reader, about 7 g/s at idle and about 12-15 at about 2200 rpm, no WOT testing.

is it possible my reader isn’t properly clearing the fault or could there be a wiring issue even though I’m able to read MAF values that the code comes up immediately at startup. It’s not a historic fault but a hard current fault.

stock tune and original fault was noticed while performing a drive cycle.

any ideas?
 

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There’s something wrong with your MAF. I’ve had a MAF fail / skew the readings in the high rpm range that would set that code.

So, it’s either your MAF or the wiring to the MAF that’s causing the error.
 

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Discussion Starter #3
Thx Skip, that’s what has me confused. The MAF on there now is from my other goat and I’ve never gotten a MAF code from it.
Also, unless an intermittent wiring issue, I can see MAF data on my scanner. Will put more miles with this MAF and see what happens. Sounds like I might be hunting down a broken wire.
 

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do you have a K&N? Clean and re-oil it recently? If so the issue is excess oil getting on the MAF element and screwing with it.
 

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Discussion Starter #9
Welp - got it fixed but not after some shenanigans. You see I first got a CEL while doing a drive cycle. I checked MAF g’s/sec and it seemed normal relative to another goat I have. I swapped in a known good MAF, cleared the code and would get an immediate fault but no CEL. Now I’m stumped. Drove a few miles to let it recognize the newer, working, used MAF and no change. Drove fine. At this point figured I have 2 bad MAFs so start checking vacuum, power to MAF, etc. All that checks out and during the next drive I felt it buck hard for the first time and decided to just buy a new MAF, PCM showed a ending fault, swapped in the new MAF and no more codes.

not sure why the pcm kept throwing hard codes when I swapped in the good used MAF but maybe that one is on its way out too? I’ve never got a code in the other goat for it?

anywho, P0101 done.
 

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Check your MAP sensor, and the grommet. Check for any vacuum leaks near the sensor.

Also, i've had replacement MAF sensors read for junk. Buy acdelco or denso replacements.
 

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Discussion Starter #12
Got a Delphi from naper,( NAPA)

I saw that for some reason the pcm is programmed to use the other sensors to double check the MAF readings, kinda of like a MAF tune based on speed density, I guess. I really thought this was the issue- either low vacuum or bad MAP sensor making a bad reference for the MAF cross reference.
Vacuum was good, fuel trims and gauge prove this and MAP on both cars were within tenths of each other.
Forgot to mention this previously. Tried to go as far as check frequency but the custom PID on my BT OBD2 reader didn’t work.
 

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Yeah, the PCM will look at the manifold pressure reading, and if it doesn't corellate to what it expects to see from the maf, then maf code.
 
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