O2 Sensor Replacement

I have a 2004 Quad Cab V6 auto. One of my rear O2 sensors went bad at 70K miles so I decided to replace all four. The two rear sensors were difficult to change because the electrical plug was hard to get to. The front two were IMPOSSIBLE to change because the connectors are totally hidden on top of the transmission bell housing. I tried until my hands were all cut up and decided to call in the “professionals.” My local garage tried and couldn’t get at them either and told me they’d take the rear transmission mount loose, drop the trans. down to get at them if I wanted them to. I declined. It still really bothers me though (and I’m really ticked at Chrysler for this kind of bone head engineering) and I still want them replaced. Does anyone have a trick or advice on how to replace the front two sensors?

What Does The 2004 Dodge Dakota Service Manual Recommend ?

Removing front wheels and plastic inner fender liners doesn’t help with access ?


Going in through the fender liners would help if accessing the sensor was the problem but that’s not the case. I can get on them with a wrench from below just fine. The issue is the electrical plug, it is firmly lashed to the top of the transmission and can’t be pulled out into view. This section of the wire harness is secured every few inches along the centerline of the transmission and the O2 branches appear to be only a few inches long. This puts the plugs in the very narrow space between the transmission and the floor of the cab. It is impossible to get a hand into this space and pulling on the wire gains almost nothing. I am furious with Chrysler engineers for making a maintenance item so difficult to change.

Visit your Dodge dealer.

You have a 8yr/80k federal warranty on emissions related parts.

It would be a warranty issue if the sensor(s) was bad but I’ve already replaced the faulty sensor. Changing the front two sensors is strictly a proactive move on my part. I’d like to know how the front sensors are changed regardless of who does the work. Short of dropping the transmission I don’t see a way.

Crown Vics are the same way…The factories do not give a fig about serviceability…They just don’t care. The dealership mechanics LOVE stuff like this. They get big labor hours to service these cars…

Having done it, all I can say is it was a total feel job with my hands only on my '01. I did find that if I got right on top of the engine itself, I could see enough of the connectors to undo them and hook them back up again.