I don't know which bank is #1, but isn't sensor #2 the downstream sensor behind the cat? On 1/8/06, David Toppin <dave at pelletizer.com> wrote: > Does this look like an O2 sensor to everyone? > > P0141 O2 Sensor Heater Circuit - Malfunction (Bank 1 Sensor 2) A > > Anyone know which side bank 1 is?