I have 2015 ford f150 5.0 about 140k
all the sudden I had code P0390 and P0394
I replaced the sensor and I even replaced the plug because I thought maybe its wearing off and not getting enough good signals.
still getting check engine code. shows permanent. I clear it it come back
truck idles weird, seems like it lose some power.

I have forscan, and it shows everything is normal. can anyone help me please figure out what's going on so I can get the truck running. I am moving to another state in less than 3 weeks and I am trying to get this resolved before driving for 6+ hours I attached a pic of the for scan


thanks a lot

 

Unplug the electrical connector of the sensor then run a scan again, do you get more DTCs, if you do, what are they.
If you don't, it's a sign of wiring issue than the sensor itself.

 

okay thank you so much I’ll try that tomorrow. But I did cut and replace the wire yesterday. I thought it was maybe the wiring is getting old so I cut it and installed a new harness.

 

when I unplugged it I got those new ones p0365 and p0369

and the p0390 and p0394 still there

 

Anyone ? Do I need to take the the cover and look where the ring is and inspect ?

 

I don't have diagrams on your 2015.
You said you replaced the harness, I assume it's just the repair harness, the electrical connector only. What else you need to do is to locate each wire, and the other end of that electrical connector, Then you can test continuity, voltage and resistance so you can check and see if anything is short to ground/power/open circuit.

 

so check this out I think I found it

I ran continuously circuit test from probes of the plug to the pcm

one pin 21
the other pin 37

37 beeps u an getting signal full circuit
21 no beep it’s dead so I have a short somewhere or cut somewhere so I’ll be looking and tracing that Line from the plug to the PCM and I will update what I found

 

When you test continuity make sure you disconnect the electrical connectors on both end. You can also swap the red and black at your DMM in case there is a diode in the circuit (one way flow). Don't fully count on continuity test, you need to check resistance too.

 

Yes I’ll check resistant and I had the battery disconnected and also I had the sensor unplugged when I did that

 

I found the wire and I fixed it and now it’s running good thanks
alot everyone