The total fuel system was destroyed including cleaning out the fuel tank. All was well until mileage 126322. I had engine light problems for about 4,000 miles before this. I took it to 2 dealerships and they reset the system and the light would not come on for periods of time. Finally I took truck to a duramax specialist independent shop and they found the DEF system defective. They replaced the heater element and other parts to this system. I got the truck back with a bill of 1500.

I drove it about 200 miles and the engine light came on again. I took it back to the independent shop and this time the reading was low pressure fuel rail sensor, I took it to the dealer hoping to get some warranty because this item was replaced under the warranty repair. This repair cost me 3000.00 less 300. warranty or 2700. out of pocket. It was at this time I found out the the CP4 pump was replaced and not the CP3 up grade. I was not told about this option until the repair was already done. I am afraid this pump will also break apart and this bill will be beyond what I am willing to pay to correct the issue. I am selling the PU and after purchasing 12 GMC vehicles I am finished with GM. I will buy from another manufacturer.