I realize my trucks a bit different than the ones most of you guys have, but my 02 is doing the same thing. I hear it at all times other than 3/4 throttle or more. I've tryed all kinds of additives to clean the fuel system out and keep it lubricated but the noise hasn't changed any. I'm planning on doing a set of higher flow injectors soon, I'll let you guys know if that cures the pinging noise if no one gets their's fixed till then.