Had similar problem with a CEL, read bank 1 upstream which when I bought one it was more than double what the downstream cost. My CEL went out after a couple of driving cycles but came back. Changed it out with a Bosch O2 sensor and 30k miles later all was good. The old sensor was snow white like it was running lean and I was getting some pinging under load. All good after replacing.

 

 

I can't imagine that a computer issue would pop up after 105k miles that need an update but maybe it does. I don't mind paying to have things fixed the right way, but it does frustrate me that the dealer wants to charge 100 to diag it then another 120 to update. you would think i could just tell them to update it and be done...

I trust my mechanic, but he can't do computer related updates. I also assume that if one sensor is going out the others aren't far behind, so perhaps i should replace all at once.

Looking at rock auto the driver side before the cat seems to be about $90
https://www.rockauto.com/en/catalog/ford,2010,f-150,5.4l+v8,1444700,exhaust+&+emission,oxygen+(o2) +sensor,5132

I always like to replace with OEM or better. My goal is for this truck to last another 100k miles if possible.

I should also mention that over the last year i've noticed a loss in power and the exhaust smells when i first start it. Maybe it's related.

I'm in the south dallas area, so if anyone knows of a dealership that is more reasonable on the pricing of computer updates please let me know.