By "correct ones" he means that there are FOUR o2s on the car.
uppers and lowers, one of each for each bank.
if you replaced the downstream sensors that will have NO AFFECT on the codes.
just because the code went away for a while means nothing.. the code test isn't run when you start the car.. it is only run after a very specific set of things are done (speed, steady state driving, temperature, etc). It can take you a few days to meet those criteria, THEN the test ran and popped the code.
Now you're sittin there thinking "shoot.. it worked for a week"... when resetting the code without touching the car would likely have made the CEL stay off as long.
EDIT: with both codes being present, and at the same time-period, I would suspect something other than sensors.. such as a gross leak, or fuel mixture problem.
Ray
