Another Low quailty DEF/Cel p20ee p27f

[s10aromeo]

Picked up the truck again today.The dealer intalled the new uera injector.The 9th injector is still on order.All the cels and low qauilty lights are off.The dealer told me to drive it around.Should I drive this truck around with a backhoe bucket in the bed from now on so I don't have these problems again?One more trip to the dealer and I will be out of the woods and then some.Before this I drove alot of city and didn't haul much for the lat 10,000 miles.Truck has 11,00o on it now.

[skidoochris]

others have posted same problem and the fix was a new NOX sensor

[s10aromeo]

I went plowing today with large backhoe bucket and 9 foot plow.I have a low quality light and CELS.While driving job to job I was above 50 mph.I had the low quality light go out and I hope the CEL is fast to follow.Still waiting for the dealer to order the "9th injector" for the exhuast.Fun FUN.I am thinking u really have to work these trucks to keep them happy.I think the truck likes 1500 to 2000 rpm for less rejens.If you hammer it more I bet you regen more.I duno.

[s10aromeo]

The CEL I had on(didn't scan the code this time)went out.I have been driving around with my plow/backhoe bucket becuase of all of the snow and the truck likes it.Lets see how long low qaulity/CEl's stay off while "driving the truck correctly"..IF no lights come on I don't plan on going back to the dealer.When The tech reinstalled the iner fender well/splash gaurd a couple of plastic pop fasteners were just hanging there not even clipped.I duno I hate hafe ass work.Goes to show you what type of tech the dealer has.I still have a rejection sticker on since august from all these repairs.Truck plows like a beast and I am very happy with the "feel".LTZ all the way.

[s10aromeo]

well it's been a couple weeks and the lights have been off.But today I went plowing for the 4th time this year and all of the other times the lights were off.But same codes and def lights came on today.I am loader with buckets and plow driving around trying to get this light to shut off.I made another appointment at the dealer.It's been said a thousand times I need to grow some nuts and take all this def/dpf stuff off.

[redwngr]

Is it a 'DEF quality poor' message that you are getting?

Have they replaced NOx sensors as part of the 'repairs' that have been done?

[s10aromeo]

Yes it's a poor def message and two codes

[VetJet]

I work for a rental agency in south Texas and I have personally sent 8 2012 Chevy 3/4 and 1 ton trucks to the dealer in the last 4 months and they all needed NOX sensors. Some had 10k miles and others had 40k. One even needed 2 NOX sensors. BTW, these sensor are not covered under the emissions warranty and they are expensive. We have customers who let the trucks spend alot of time idleing and driving slow in chemical plants or out in the field on work sites. Now I know usually this causes a dpf problem because you must drive the vehicle on the highway above I believe 50mph for the dpf system to clean itself but I was led to believe that the NOX problems where caused by the DEF system not the DPF system. Sure is strange that GM just happened to not include the NOX sensors in the warranty that should be 100k miles. Can anyone tell me why GM did this if they were not expecting to have problems with the NOX sensor?

[redwngr]

They should be under warrany, they are necessary for the emission system to function they way it was designed.

[VetJet]

Thats what I thought, too. So the head of our company (we are all over the southern U S), anyway the head of company that handles warranty issues called GM and they told him they were NOT covered and offered to rplace the first one under some special program for fleet owners, but the others not so lucky. I have one at the dealer now that we pulled out a week ago and put back into the dealer the same day now they tell us it needs another NOX sensor, one one each bank, and I have another truck in thathas the same symtoms as the previous ones plus the DPF system is not cleaning itself. What happens is they get rushed by the government to come out with a new system in 2-4 years for emissions and it takes auto manufacturer 10 years to develope the system but they only have 4. so I expect it to be 2018, 2019 before they get these system to work properly. also these systems are new so the mechanics have to learn how to diagnos and repair them.