After a few month, I finally got my 87 f150 back on the road. See post: https://www.f150online.com/forums/pr...backfires.html

The only two error codes I am getting know is 41 (O2/HO2 Sensor) and 25 (Knock Sensor) and can not find their locations.

For the O2 Sensor, I know it is located on the passenger side, but looks like it has been removed along with the CAT. Converters, just a muffler now. I do see a place on the exhaust manifold where it looks like it goes, but can not find the plug or where to plug in the new one O2 Sensor.

From what I found online, looks like the Knock Sensor might be on the passenger side also. Also can not find a plug for it...


Thanks in advance...

 

The Knock sensor is behind the intake plenum, standing upright just right of the center of the engine. The O2 sensor should be on the exhaust manifold just before it goes into exhaust pipe. It has a 19 inch lead on it so the plug should be about that distance from the actual location of the sensor.

 

The problem for the O2 sensor, it looks like it has been removed, and trying to fine the wiring plug it plugs into...