I have a 2000 Dakota Quad Cab with the 4.7 Magnum engine. The check engine light came on and got a code P0155 - brought it to my local mechanic, he replaced the O2 sensor and told me to not be surprised if the check engine light came on again (as there are 4 sensors). Light came back on, took the truck to another mechanic who informs me that the O2 was replaced but not connected. (1st mechanic must have replaced but not connected it?) They also stated that the wires were "crushed". They won't pass the truck because of the check engine light. They want us to get the harness replaced.

My brother-in-law and I raised the truck, removed the wheel well trim, it looked like neither mechanic had done this completely. We noticed that there were a blue and black wire coming from the engine block. Looked like someone had cut them. We checked the O2 sensor and didn't see any wire leads just the ones that lead to plug. My question; what are the blue and black wires coming out of the engine block? and are they connected to the O2 sensor somehow?

I plan to take my truck to a dealer this week and have them look it over, but if I can save the $$$ it would be great.

Thanks

 

I've checked a couple of diagrams that I could find and can't find any diagram that shows those two wires, what they are or if they connect to the O2 sensor.