Hi All, The check engine lite has been on and off since Dec in my 2002 Explorer 2x4, 4.0L v6 - I have had it in the shop three times and each time I am told the problem is an o2 sensor - I have had two of them replaced, and both of these places have told me they see nothing else wrong with the vehicle. But the light keeps coming on and each time is codes out as an o2 sensor. I have stopped in a third place and had them hook it up and the tell me the same thing, Bank 2, sensor 1, PO153. Looking under the vehicle I see 5 o2 sensors and one of them has the grey/black/white wires cut and is gashed as if I ran over something and it cut into it. From the info I have found online, I thought this vehicle only had three sensors? (1st question) 2nd question - if there is one on the drivers side and two on the passenger side, why are the passenger sides ones about 3 inches apart? 3rd question - if the first one on the passenger side is the damaged one, if I buy the part, where does it plug in. I have a photo if that would help.