Skylark V6-3100 3.1L VIN M SFI (1996)
Pictorials of the designation of oxygen sensors in General Motors vehicles.
There has been some confusion relative to OBD II oxygen sensor designation. The intent of this bulletin is to eliminate misdiagnosis of those oxygen
sensors due to misidentification. When using Section 6E of the Service Manual, this chart can help locate the appropriate bank and sensor for the
diagnostic.
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.
Just a reminder, the OBD II P-codes, technician observations and customer comments are all to be recorded on the repair order in accordance with article
1.6.2G of the GM Service Policies and Procedures Manual.
Use the approved labor operation for the sensors replaced. J 6372 is used for engine out sensors. Labor Operation J 6380 is for the pre-sensor (the sensor
just in front of the catalytic converter) and the post sensor (the sensor behind the catalytic converter).
