[tblake]

I hardly ever replace the rear sensors in anything of mine unless there is an issue with it. The rear O2's are only there to monitor the Cat Effiency and it has nothing to do with drivability. If you have the old rear ones still, try swapping those back in.

The front O2 sensors in my pickup are both Denso brand. No issues, but the darn things were about 75 bucks each. With O2 sensors I usually stick with stock delco's or denso I have had good luck with. I got my Denso's from AutoValue and they come with a 2-yr warrenty.

Which your bosch O2's could be under warrenty also.

Let us know how things turn out.