122andy
Observer
(Regarding an 02 full size Montero) I didnt see that this have ever been brought up in discussions of o2 sensors. Most everyone mentions that all 4 are the same part number and are interchangeable, which is true to an extent. Say, you track down a bad upstream drivers side O2, and you order one thinking they are all the same, and receive a black connector, it wont plug in without trimming the plastic tabs off. The downstream on the drivers side is a black connector. Its just the opposite for the pass side. Upstream is black, downstream is grey. There is no mention of any of this when ordering and trying to specify which you need, a black or grey connector. And I havent seen it mentioned on here. Just make sure when replacing them all you have two grey, two black. A bit frustrating to say the least when I tried to replace just one.