what o2s did you replace? if you didnt do the upstream also on bank 1, id start there and see if it goes away

 

I replaced the rear O2 on each side. I didn't have codes from any sensor except the passenger side downstream. I don't have money to buy a sensor right now, especially if I don't know for sure that it will fix the problem.

 

the you need to know for sure... this code is stored when the ecu sees the down stream switching at near the rate of the upstream9it should switch a good amount slower, ie working catalyst) so, either your cat isnt doing what it should, or your upstream is switching slow, sometimes they dont throw the codes that they should. best ways to check are your o2 sensor voltages and your cat temperature. if you have a infered thermometer, check yours cats, right before, and right after them. should be hotter post cat.