ok so a friend of mine with a 01 bravada is getting this code and is a heater circut bank 2 sensor 1 which im thinking might be the post CAT o2 sensor but i thought the post cat o2 sensor code were in the 140s since the pre cat ones are in the 130s

ive also heard grumblings that this thing has more than 2 sensors for oxygen



1989 Turbo Trans Am #82, 2007 Cobalt SS G85

Bank 2 sensor one is a pre cat o2, Its on the #2 cylinder side, and yes the bravada has four 02 sensors tow pre cats cats and two post cats. Just check the power wire for 12volts, and make sure the ground wire does not have any voltage on it. But it is most likely just a bad O2 .