I have a new fuel pump, ACT sensor, the MAF is clean (I am getting a new Pro-M though), and the O2's aren't throwing any codes. I have heard though that the 02's my not make codes? I will put the timing back down to 10* and see what happens. It may go away with my new MAF though since I have heard that solves so guy's problems. It doesn't ping when I maintain a constent RPM, only under partial acceleration or WOT. Don't know if that helps.