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mass air flow problem please help!!!!!!!!!

64K views 10 replies 7 participants last post by  Dooner  
#1 ·
i have a 2008 duramax. i tow alot of heavy loads. lately, if i get on the gas hard it is very sluggish. truck wont raise much over 2000 rpm, is very slow, the reduced engine power comes up and check engine light. i took it by orileys and they put computer on it, says its mass air flow sensor. i bought cleaner and cleaned it, pulled onto road stomped it, and same result. no power.and engine lights, and reduced power.i use this truck for work in the woods, not to ride around and look pretty. no mods except for a piece of **** bully dog. wanting to do a dpf delete. any ideas on maf sensor fix?and yes i know i have to get a different programmer...... please no advice on performance stuff right now justg want opinions on how to fix current problem. thanks alot.
 
#4 ·
When was the last time you changed the fuel filter?
 
#5 ·
It could hurt to try a new air filter if the one in the truck looks dirty. If driving in blowing snow the truck will sometimes throw that code and you can find the air filter box full of snow. If working in alot of dusty spots might have a similar problem.
 
#7 ·
i took it by orileys and they put computer on it, says its mass air flow sensor. i bought cleaner and cleaned it, pulled onto road stomped it, and same result. no power.and engine lights, and reduced power.
My experience with MAF cleaner is that I cleaned my MAF one afternoon, reinstalled it and a couple of minutes later started it. I got a CEL right away. It only takes a few seconds for the cleaning fluid to dry so I was concerned that I did something wrong. Tried starting the truck several times thinking that a few key on-off cycles would clear the CEL. It didn't clear. Went to the internet searched and searched for a similar situation and couldn't find a thing. I was convinced that somehow, the cleaning damaged the MAF and I would have to buy a new one.

Next day, started the truck, CEL light now off, and the truck ran great.

It could be that you just tried to run the truck too hard, too soon. Try using it in a normal (little 'ol' lady) fashion for a couple of trips to the store, fuel station, etc and see if it doesn't clear up on it's own. Also, you might want to double check the installation of the MAF. It's pretty sensitive to how it is mounted. Can't have any air leakage thru the gasket area.
 
#9 ·
Was it P0101? Dirty, not fully seated, or other than AC Delco filters are the most common reason for setting a P0101 but they usually do it at idle or low load. The EGR system is also another one that really plays with air flow through the engine and loves to throw a P0101 and may not necessarily set a P0401 for a lack of EGR flow. The fact that yours is doing it under high load makes me think you have a fuel delivery problem and the mass air flow code is setting because the engine isn't doing what the ECM is telling it to do.

I had an 09 that from 70,000 miles on had constant P0101 issues. I smoked tested the entire charge air and air cleaner side of the intake and never found a leak. With the help of tech assistance at 95,000 we condemned the EGR cooler as it was restricted just enough to throw the mass air reading off at idle and set a P0101. Finally it made it out of warranty and we did a DPF and EGR delete via tuning and with a block off plate and the damn thing started setting the P0101 again. I turned off P0101 and it finally made a truck out of it. I just did the 20/20 tune on it and now it actually runs like it should have since new and gets in the high teens on the highway.
 
#10 ·
Whenever I hear 2K RPM max,it usually is fuel related such as the P0087 low fuel rail pressure code which is EXTREMELY common.Why not get another scan done somewhere else with a scanner that's more sophisticated than the one at Oreillys?
 
#11 · (Edited)
I used to get a CEL for the MAF sensor quite often. After cleaning it properly several times with MAF sensor cleaner & re-installing it, I realized one of the mounting screws wasn't tightening fully, allowing it to seat properly into the plastic air inlet tube where it's mounted. A slightly larger screw did the trick for me, although I can't say I had similar symptoms as you've described.