ok i had to change one of the stock senors on bank 2(downstream) cause of low voltage, when i did i cleared the codes and then went driven around then in 30min the check engine light comes back on and get it check and it says that bank 2 upstream O2 senors is running lean. any ideas
change the upstream sensor. try swapping the front sensors from side to side and see if the code changes to bank 1 or if it stays at bank 2. if it changes, then its the sensor, if it doesnt change, then theres a genuine lean condition.