i have a 2000 TA and two codes came up! bank1 sensor 2 and bank2 sensor2. i replaced both after cat o2 sensors and then two days later the same codes came up!!!!!! WTF!!

 

so you do have cats? or do you have headers? what is youe exhaust from the manifolds through the cats if you have them? is the car running wierd if so describe it. i had this same problem for a while but i have LT's and an ORY pipe so i was blowing out my front 02's i know you said yours are the rear though.
ON EDIT: i forgot to mention that i have my rears deleted from the system with LS1 edit.

 

Are the codes P0420 and P0430?

 

I had this problem earlier this year. One thing you might want to check is that your MAF sensor is clean. The problem I had was the oil from my K&N filter coated the thin wires on the MAF and caused the computer to lean out the Air/Fuel Ratio.

Something to check.

 

thats what i was thinking cause this happened to me as well and i just cleaned my MAF and all was good but i was having a serious power problem and that was it. cleaned it and i was good to go, i cant remember if i said that earlier or not. i am about to go and have a look at it again to see if it is what is causing my low idle problem.