Ok, looked at the wiring diagrams..... O2 heater circuits go thru the ASD relay, which, if the engine runs, is working properly....... (sorry 'bout that....)

Check Fuse "K"..... that's the heater circuit for the O2's.

 

Can you explain what or where fuse K is. Thank you

 

In PDC, in the group of fuses toward the front, and outside of the truck. It's the one closest to the fender. (should be a diagram on the underside of the cover for the PDC.)

 

Yes that’s where I saw the o2 heater relay. Right next to the battery right? The diagram shows the relay for both front and rear o2 heater. But the places shown for heater relay is empty

 

Yeah, evidently they changed their minds about where to get power from, and didn't change the design of the PDC.

 

What could I do from here

 

You still have the codes.... so, time to start testing at the O2 sensor connectors. With the engine running, should see 12 volts (or, battery voltage...) on the Dark Green/White wire, 5 volts on tan/white wire for the front O2, and on the orange/black wire for the rear.

 

Should I check the rear o2 (downstream) because the front upstream fluctuates and the downstream stays at 1

 

Yeah, start there, see what ya get.

I don't recall, have you replaced the sensors??

 

I replaced both the sensors before, not after my drive to the gas station and the code p0141