Bad performance and DPF, low power faults - I have a 2007 GMC 2500 HD 4x4 with 6.6L DMax. I installed a K bake off and they noticed the K ...

I have a 2007 GMC 2500 HD 4x4 with 6.6L DMax.
I installed a K & N Filter and almost immediately experienced problems. I had the DIC warning that the engine was producing low power, acceleration was about the same as a bicycle, and I had the particulate filter cleaning fault. My fuel mileage tanked down to about 7MPG.
Was under warranty so off to the dealer who was going to do the DPF "bake off" and they noticed the K & N filter. They wouldn't touch it and said to switch back to stock filter. Luckily I saved the stock filter and immediately reinstalled it. Problems went away and performance, fuel mileage, etc went back to normal.

What gives? Has anyone else experienced this? The DMax can run a K & N filter right??

First off welcome to the site. I havent heard of a filter causing that much havoc. But the dealer may think it has something to do with the oil residue from the filter causing issues maybe? You can try a dry filter. See if it gives you the same problems, Also try to take off the negative wire on the battery while you are doing the install. Let the computer reprogram itself.

Thanks for the welcome koolz71.
I'll try your suggestion, I think you're on to something. The DPF warning boiled down to "There's more air coming in than exiting" based upon stored performance in the computer? The MAF fault was not due to an oily or dirty filter, I didn't oil it, I installed it new from the box. I took the MAF sensor out to look at it and it is as clean as can be. I think that boiled down to a large increase in mass air flow compared to previous performance. So, I'll give disconecting the batt a shot and see what happens. THANKS!

Welcome to the site, Also another question arising from what koolz71 said, if you remove the negative wire from the battery, would you loose the security on the radio and if the answer is yes how do you find out what the code is and how do you put it back after you loose it. Sorry to jump in on another topic, but it was also a welcome to the site for mtank.

Hey I just noticed I am running on 8 cylinders lol

you shouldnt get locked out of your radio..i think it will only require a code whenever the radio is disconnected. I have never had to enter in my security code...but thats my experience