I am really hoping someone can help with this. I am trying to replace my O-2 sensor on my 86 ford f150 302 EFI. I only have one wire comming from the sensor and I cannot seem to pull the wire of the sensor. Does it come off and should I only have one wire? According to the Haynes manual the wires should pull off and the picture shows two wires.

Thanks

 

There is only one wire, and it does not come off the sensor. The other end of the wire coming off the sensor has a gray plastic connector, which you will need to unplug.

 

And, if you can't unfasten the connector, not a big deal. Just cut off the plug and use a Butt Splice to reconnect the new one. The new one probably doesn't have the same connector anyway.

 

Eh, the one I installed did - it was the Bosch from AutoZone. It's about the same price as the "universal" one that you did have to use the butt splice on; there's about a $1 difference.

 

Thanks, I have the new sensor and I am trying to unscrew the old one from the manifold. I am having a heck of a time. I have tried it cold and hot and I cannot get it out!!!

Anyone with any suggestions?

 

1. Buy Kroil penetrant. (Failing that, use PB Blaster penetrant, which you can get at AutoZone. Anything else will NOT work).
2. Buy oxygen sensor crowsfoot wrench. Also, get Craftsman 1/2" to 3/8" socket drive adapter (if you don't have one) as these wrenches are usually 1/2" drive and you need the spacing of the adapter anyway.
3. Return home and allow truck to cool off.
4. With the truck cool, apply Kroil or PB Blaster to the O2 sensor threads in the manifold. If you can't see any threads, simply flood the area between the exhaust flange and the sensor; the penetrant should soak in. (Best done from underneath the truck.) Wipe off any excess that is not soaking into the joint so that you do not have an exhaust fire when you restart the truck.
5. Wait 15 minutes. Tapping the sensor with a wrench end lightly every few minutes may help the penetrant wick into the threads.
6. If you are not under the truck, get under it. Slip the sensor wrench over the sensor, with the flange *up*. Attach the 1/2"-3/8" adapter to your ratchet, and insert it in the appropriate drive hole from the bottom. Make sure you have the ratchet set to turn in the correct direction, and that you don't try to tighten the thing in.
7. Loosen the sensor. It may take a bit of effort to start, but it should come right out.
8. Once you have removed the sensor from the exhaust, carefully pull it out and up from the top of the truck and trace the wire back to the connector. Unplug the connector. (I had to use a small slotted screwdriver to release the tabs. If your new sensor has the correct factory connector on it already, feel free to break the stupid tabs off because you will be installing a new connector with the new sensor.) Be careful not to pull the connector off the vehicle side of the wire.
9. To quote my favorite British manuals, installation is the reverse of removal; the lone exception is that you do not need to apply penetrant to put it in, and you need to be careful not to crossthread the sensor in or damage the body of the sensor during installation.

This successfully removed a severely stuck sensor that two strong men hauling on a wrench could not budge.