My 06 had a really bad chattering sound comming from the motor when I would get on it or especially when I was pulling a load. I took it to the dealer and they said it was a fuel issue and I needed to add more injector cleaner and drive it harder... well none of this worked so I took it back and they ran some tests on the injectors and they were dumping too much fuel in. They ended up replacing all six injectors under warrenty and now my truck runs like a top again!! No more pinging... but now it won't smoke like a banshee anymore!!:{