p0101 code

[diesel71]

I thought I would share this simple fix as it took an act of god to get the customer to believe me. 2009 chevy 2500 6.6 duramax,check engine light on in limp mode with code p0101.

shop #1 you need a mas air flow sensor/ sensor connector/ fuel filter and an oil change. ($ 800) next day lights back on didn't fix it.

shop#2 you need a different mas air flow sensor/ we will fix the bad wire connections and clean your intake tube. ($600) next day lights on in limp mode didn't fix it.

shop #3 you need a engine wire harness ($1200) he opted to not have it done.

shop #4 the gmc DEALER, you need the oem mas air flow sensor,the one you have is aftermarket and don't read right. there is a ecm update that should help with your problems.($600). next day lights back on didn't fix it.

shop #5 lucky me. listen to story and all the money spent for at least an hour. get the truck in diagnose and take some short data movies. called customer and say you need an air filter, what the @@$%#$%% do you know what your doing that truck has been to 3 shops and the dealer, there's no way it just needs a filter. I try and explain how and why he needs a filter but he just don't understand. now I have never done this this before but I tell him if it don't fix it ill give his money back,he agrees picks up truck.
this truck had a k&n cleanable filter in it,looked clean but was restricting the air flow enough to cause po1o1. the g/s per sec was at 21g/s with a new filter its at an average of 33g/s with no filter its at 33 g/s.
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[Witsend]

Nice catch ,but I think I would wait 24 hours before posting that I fixed it just in case Murphy might be laughing out loud tomorrow.

[hhong12dlm]

"k&n cleanable filter in it,looked clean but was restricting the air flow enough to cause po1o1. the g/s per sec was at 21g/s with a new filter its at an average of 33g/s with no filter its at 33 g/s"

You gathered info and evidence and came up with a solution.
That's awsome, I wish everything worked out like that

Thanks for sharing, enjoyed the story

[Crusty]

That is just too, too funny-!!!
Especially the comment "took an act of god".....
Had a similar experience about 20 years ago. Ford pickup truck. Those air cleaner boxes would seize the screws and the threaded metal inserts would spin loose in the plastic. THAT took an "act of god" to get to the air filter...lol
The truck had been to shop "A" with $600.00 blown. Then it went to shop "B" where another $500.00 blown. Then it went to shop "C" where another $700.00 was blown.
No codes but it ran like a hamster wheel was all it had for an engine. Scanned the data and that indicated it wasn't breathing right. Fought with the lousy air cleaner housing design to get to the air filter without destroying it for about a half hour. The air filter looked similar to this one.
Billed the guy for a scan. Billed the guy for the half hour time to save his $400.00 air cleaner. Billed the guy for the new air filter.
Problem solved.
The idiot got mad at ME for fixing the truck-!!! Apparently we weren't supposed to bill him for anything but the filter.
Those K&N junk things make me laugh every time I see one. How much crud has that thing already let into your engine-??? (when they're "supposed" to be making more horsepower-!! LMAO)
The one you had was restricted which is funny 'cause those things are using the old "oil bath" principle from the 1940's....
GOOD WORK Diesel71.
You went back to fundamentals before you threw a software update and a new ECM and another MAF sensor and replaced the "clogged Cat"...
It's the kind of workmanship I've come to expect from you. GOOD WORK-!!
Thanks for the giggles & grins....
K&N....laugh, laugh, laugh....

[greasybob]

Known good data, just as important as known good wave form. Nice work!

[Matt]

Me Too!

I had this same thing happen to me a month ago, same make/model code. The customer had not spent the amount of cash yours did before it came to my shop though. I was able to resist the temptation of replacing the MAF. After following the trouble shooting flow chart, I had a look at the air filter housing. My customer did have a factory air filter however. Upon inspection I noticed it had not been installed correctly. The lower portion of that round filter had not been fully seated into the ducting. The filter element did not appear that dirty but I ordered a new NAPA one anyways due to the deformed body of the incorrectly installed original one. With the new filter installed correctly I test drove and monitored live MAF data and didn't notice any real increase in grams/sec. I just attributed the P0101 to the possible intermittent sealing and unsealing of the air filter in the housing. The P0101 never came back and the truck never went into "reduced power mode" after the air filter install.

P.S. Thank you for sharing your diagnostic data and great tip.

[greasybob]

Maybe Shop Key should put a disclaimer one the 1Search Fixed It page. Something like what's in VW scanner menu. "Do not replace parts based on codes or statistics alone, do your own research !" Replaced MAF, 15 Fixed Its !! Who can argue with that. Swap-tronics indeed. At least if you dig a little deeper you can find the correct specs.