Originally posted by PHiZ
I don't think you have a heated 02, but I could be wrong, post your full car mode/year.
The CEL code won't show a heated o2 fault if the car doesn't have a heated o2
02 sensors measure A/F and they use pressure in their calculations, so that might be messing it up.
The o2 sensor doesn't measure pressure at all, nor does it make any fuel adjustments based on pressure. That is the MAP sensor's job.
Chip your car, you'll be OBD1, and at that point you only use the forward 02 sensor location.
He's in california, aka, not allowable. Then again, having no cat is a no-no as well...