check engine light and codes

P0132 and P0138, both pertaining to O2 sensor high voltages. This came on while wheeling, ran like crap after. Any ideas? my rear O2 sensor is only a few months old...what else can cause a high voltage reading on an O2?

Bad wiring or broken/loose connections. Inspect the O2 sensor wires for damage and melted or abraded insulation. Since you were just messing with the wires it would be reasonable to suspect that they came in contact with the drive shaft or exhaust.

my after-cat sensor threw codes a lot, and then i just adjusted the wires and the problem went away. original O2 sensors after 140K, still runs like a top