O2 sensor

[ponyboy762]

The engine light has been on in my 89 coupe ever since I bought it, and I decided to change my O2 sensors to see if that was the cause. It's been running rich and its been chugging gas like crazy. When I bought the new O2's the the wire harness was different and didn't fit. My buddy had an O2 out of his 86 GT and it matched. I checked all of the wiring and it seems that the wires starting around the mass air, going to the O2s are out of another car. As if that wasn't enouph, I tried pulling codes and the computer won't talk to me at all. Could all of this be caused by the O2s and wiring or is there a way to test the computer to see if that is bad too?

 

[Mavrick]

Are you sure you didn't get o2's meant for a 94+ car? I think the 94+ cars are a 4 wire o2 and the pre 94's are only a 2 wire setup. Not sure on that though.. but i know they changed either in 94 or 96 ?

 

[noslow5_0]

pre 94 cars are 3 wire..... 94 and up are 4 wires.... as far as your computer situtation goes, you may just want to start tracing wires back to the computer. Im sure jrichker or someone will be here to give you the diagram soon, but i dont remeber the website off the top of my head..... So bump for you!!!

 

[jrichker]

As requested...

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

http://www.veryuseful.com/mustang/tech/engine/images/88-91eecPinout.gif

 

[whitemustang89]

yea dude pre 94s are 3 wire. im surprised a fox body actually threw a check engine like. my car could have no oil and have a rod hangin out the block and stil no cil.