Oxygen Sensor: Application and ID

*** THIS ARTICLE INCLUDES UPDATES MADE BY TSB # 67-65-40, DATED MARCH, 1997 ***







Oxygen Sensor Designations

There has been some confusion relative to OBD II oxygen sensor designation. The intent of this article is to eliminate misdiagnosis of those oxygen sensors due to misidentification.

For "V" engines; BANK 1 is always on the side of the engine with the number 1 cylinder (odd cylinders), and BANK 2 is always on the side of the engine where the number 2 cylinder (even cylinders) is located (see image).

Pre and Post Sensors

The pre-sensor is the sensor just in front of the catalytic converter. The post sensor is the sensor behind the catalytic converter.