The reason I changed the sensors is because I gave it a tune-up. I figured it needed it and after looking at how black the plugs were it really needed it. The check engine light was on before I tuned it up. After it threw the code I then replaced the same oxygen sensor again and nothing changed. I am thinking there is a break in the wires somewhere. The ford dealer told me that it isnt a CAT code, it means that somewhere it is unplugged or the wiring is broke. Does anyone know where and if there is a big connector in the harness for this oxygen sensor. The service manual shows me the upstream one, but not the downstream one. It looks like it runs over the transmission, but I loose sight of it after it goes up the engine. Thanks
Blaze
