Check out the connectors that are part of the fuel injector harness. This harness is subject to high heat. the wires under the UIM are usually the wires with the most dammaged insulation. I just so happen to have a brand new harness I can sell you. Part # F6RZ-9D930-S6A. There are at least ten connectors that are part of this harness, TPS, IMRC, Coil Pack, all 6 injectors, front upper HEGO, IAC, CAM, and crank position sensor, water temp etc. The price for just the fuel / charging harness is approx. $ 370 thats Bills price all four are about $2000.