P140C code

[xxiiiliv]

2012 Duramax threw a P104C code today. Interwebs tells me it’s the EGR valve. EGR valve is only 2 years old. Now, I just started treating the engine with Stanadyne injector cleaner Friday, before a quick trip to Utah. Is this possibly the cause?

 

[SCMesina87]

Have you checked the duramax forums? This might be helpful for you…

https://www.duramaxforum.com/threads/2013-duramax-p140c-and-p11cb-check-engine-codes.861009/

Someone had the same issue as you and fixed it by cleaning the Mass Air Flow sensor. Sounds like too much build up was causing the MAF sensor to give the computer erroneous readings, which resulted in causing issues with the EGR valve.

 

[jay8544]

was the EGR used for replacement OEM? Or chinese knockoff? If chinese just reset the code, may not even come back.

 

[xxiiiliv]

was the EGR used for replacement OEM? Or chinese knockoff? If chinese just reset the code, may not even come back.

OEM. Also, as I am want to do, I forgot a detail…every time we go to Cedar City, I get a MAF code which doesnt come back after I get back and clear it, so I’m hoping the same here. The inter web said this was serious though, so I thought I’d throw the question out. Oh yeah, the MAF sensor is a year old and OE

 

[ehudakine]

Have you checked the duramax forums? This might be helpful for you…

https://www.duramaxforum.com/threads/2013-duramax-p140c-and-p11cb-check-engine-codes.861009/

Someone had the same issue as you and fixed it by cleaning the Mass Air Flow sensor. Sounds like too much build up was causing the MAF sensor to give the computer erroneous readings, which resulted in causing issues with the EGR valve.

Yup it could be the problem it happen to I own a 2018 GMC, 6 months after I bought it, spray it clean put it back it might read the same for awhile jst let the computer reset itself back & should be a good ,with all the wind & dust & heat here in the valley clean your map sensor & check battery.

 

[ehudakine]

I forgot to mention I had a problem with my gas pump on my gmc it's in the gas tank I had to replace it myself mine was gasoline u got got a duramax

 

[Coup d'etat]

I get an occasional CEL in my 2019 Silverado on hot days. Never on cool days. Lean condition MAF error. Hot dry desert air doesn't agree with the truck at all.

 

[Harley]

2 year old part means nothing these days. I’ve had to replace parts on customer cars in a lot less than 2 years. The quality just isn’t there anymore, OEM or aftermarket.

 

[Harley]

I get an occasional CEL in my 2019 Silverado on hot days. Never on cool days. Lean condition MAF error. Hot dry desert air doesn't agree with the truck at all.

Clean it. In this dusty environment its easy for the tiny sensor inside to get covered and start messing with things.