Thanks for the tip on the sensors. So now Ive wasted more than $100 on Walkers. Great

i will give it a try and post back here

 

I don't suppose you can return the faulty ones as not actually working?

Oh, and while in my case the trip computer only showed FF44, the garage could read the codes from the CPU in the trunk and that showed both FF44 and FF45 (B Bank). It might pay to replace both. But see how you can read the codes from the rear computer thingy first, I guess. Unless a reader costs more than an O2 sensor....