99 Expedition oxygen sensor help

[GarrettH]

I need help, I hear that there are 2 O2 sensors on the expedition, is this true and are they easy to get to? I had a comp. diagnosis and my O2 sensor is running lean and has been for a while. I need to get it fixed and prefer to do it myself. Any insight would be greatly appreciated.

[GarrettH]

oooooo the last post made me a four point

[Texastaxi]

Usually, there's one before the catalitic converter and one after. I don't know for sure on your truck, but if you crawl under there, they'll be the only bungs, with a sensor and a wire comeing out of them, in the exaust. Once you locate the catalitic converter, go both directions and you'll find them.

The wires will have a short pig tail, and then a plug. You simply unplug the wires and unscrew the sensor. While you're at the part store, they make a special socket, that has a slot cut all the way down one side (for the pigtailed plug to come out of) that makes it much easier to get them out.

If you replace both of them (I think it's recommended), and stop for a beer between sensors, you're looking at about 30 minutes.

[GarrettH]

I was reading a little and found that they are on the manifolds???? I wonder how easy they are to get to if they are there??

[chadc]

O2 sensors are easy to replace, I have done several on Chevy's and Honda's. Find the intake manifold and locate the sensor using the same search criteria that TT provided. Replace both and take your time so to not mess up the threads. Plug em in, biggest issue I had was the resetting of the computer, sometimes you can unplug the battery or you may have to go to the dealer and have them do it. Hope this helps.

Chad

[GarrettH]

that helps a lot thanks guys