Well I guess this is what I get for saying my truck has been trouble free. lol. I had my cel go on a few weeks ago, then turned off. It came back on about a week ago for a day & was back off the following day. Then the next day I was accelerating heavily & just before the truck shifted I would here a loud noise like a blow off valve & the truck would surge. I was thinking that what I heard was the turbo backspooling because of the truck defueling. About 30 miles later the cel came on again. I got it into the dealership yesterday morning & the dealer said the code was a p2262 which means "mechanical turbo". They said they dont know what it is & asked if i wanted to do the latest flash which is AQ. AG was the original flash. On a couple other threads on here it states that the dealer is replacing the turbo with this code. Does anyone know how serious this is & also is anyone familiar with the AQ flash. The dealer said this will solve the problem & it does not derate the engine & it should also help my fuel economy, which I find hard to believe. Thanks in advance for any input!!