Had issues for long while with p0137 , and after replacing good 02 and AF sensors (100k miles so not big issue) and having dealer and another few shop run full diags. no one could find an issue so all fingers point to potential ECU issue.
i couldnt find any info on the ECU , location and removal , once i found it i figured i would post this info and it wasnt too hard.

1. follow online videos for removing glove box (search installing crawl control and multierrain ) or there might be som other vids

2. once the passanger compartment is open and glove box, moulding removed *i did leave air bag connected and on floor with some support to keep tension off the cable to it.. you will see the ECU right next to the #3 arrow to left of it left and partially covered by a black cable..

• disconnect your battery
• use 10mm socket to remove nuts on arrow 1 and 2
• use flat tip on arrow #3 to flip the tab and slide the 2 plastic modules off the ECU bracket (pulls forward)
• use 10mm socket to remove nut #4 and a bolt you cant see from pic on #5
• disconnect each harness on ecu and i marked each 1,2,3,4,5 so i could make sure they plug in correctly later (the connector might be keyed to only fit the right connection but why take chance)
• now slide backet #4 and 5 forward and might need to wiggle it a bit
• Done, ecu is out and 4 screws hold it to the bracket.

I am sending it out to one of the several places online, who will diagnose it and make sure there is an issue and fix if needed..

 

Which online did you send to, and did they fix it? How much did they charge?

 

not sure i can mention names on here. But 1 in ny 1 in fl. Both list price for diag and repair.

But noone ever solved issues so traded it in and for first time in 20 yrs i left toyota lexus trucks. I know they are reliable but got burnt on 03 sequoia frame issue and now 02 sensor error lexus and 5 places couldnt figure out...

Couldnt get what i wanted as family vehicle and daily which would be an old k5 blazer.. so moved to a 20 f150 lariat fx with low enough miles i can take care of trans fluid services and keep 10speed in better shape.

 

5.0?

 

yep. Not a fan of turbos on trucks though i tested an f150 with v8 turbo..way to fast. And i hear good things on smaller f150 eco 2.7 i think as ita apparently made with bulletproof materials.. but a 5.o v8 any mechanic can work on and fix

 

5.0 is the best power train they have by far, IMO.
2018-19 model years had some oil consumption issues related to uneven PWTA application but I think that
was sorted out for ‘20.

Good engines, WAY better than any GM V8 with DOD/AFM/DFM or the Hemi.

I just went into a 2018 F150 5.0 commercial truck with 300,000 miles, a ton of idle time and not the greatest maintenance.
Exhaust phaser failed a bent 2 exhaust valves.

Replaced the 2 bent valves/followers/phasers and it’s back on the road running like a top.

300K mile bearings looks almost like they just came off the assembly line.
They went right back in.