96 Ford Mustang GT, O2 Sensor Code question

RACINJASON

MEMBER
1996 FORD MUSTANG

Whats up guys, I've got a 1996 Mustang GT with about 95,000 miles on it and the check engine light has been on for a few months now and i've finally had time to go and get it checked out and the codes are PO136 O2 sens. B1 S2 and PO156 O2 sens. B2 S2. So im assuming that it means Bank 1 Sensor 2 and Bank 2 Sensor 2. So my question is, Are these the Sensor After the catalytic converters or the ones closer to the exhaust manifolds. I just dont know what the B1S2 and the B2S2 mean.

1 Reply

PEPPERMRJ

MECHANIC
1,158 POSTS

P0136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
P0156 O2 Sensor Circuit Malfunction (Bank 2 Sensor 2)

bank 1 sensor 2 is after the converter on the left side (left side while sitting in the car faceing forward)

bank 2 sensor 2 is the right side after the converter
but I seriously dout that both are bad at the same time

They are the rear sensors after the cat. It is odd that they both would fail if the engine is running well. Sounds more like a wiring proplem. Maybe the heater circuit or the control voltage supplied by the computer. Best to check that first or have it checked out

Most manufacturers recommend replacement of all 4 O2s @ 100,000 miles. The front 2 sensor are the ones that effect performance, emmisions and fuel economy. The 2 rears monitor the front 2 and the operation of the cats. It will not pass a smog test with the check engine light illuminated.

Good luck and let us know. :)