I have learned that pinging could be due to arching in the plug boots if no dielectric grease was used. Plug gap is listed by Ford @.052-.056. If the gap is slightly over or under this could contribute. Vacuum leaks from intake- around MAF, accordian tube, PCV hoses, TB gasket, UIM, and LIM. Ford Racing wires are supposedly crap. If the IAT or MAF are dirty or faulty hiccups and pinging will occur. And get this _- If the PS pressure sensor is faulty or there is a leak in one of your PS lines your engine will hiccup and or ping. Another thing to keep in mind is that if your car is 4 years or older then the gas cap and/ or sending unit gasket could be leaking. The fuel pump strainer also gets clogged with debris and must be cleaned. Any of these things can contribute to pinging or hicupping.
