where does the o2 sensor plug in?
My car has an automatic transmission.
Hi Wayne. Thanks for contacting us today. Back in 85, GM V6 motors only had one O2 sensor. It was considered an upstream sensor, which means that it was installed near the center of the exhaust manifold. Downstream sensors were added in the mid-90’s - which were added right before and right after the catalytic converter. You might want to refer to a service and repair manual for your 85’ Olds 88 to review the recommended steps for removing and replacing the O2 sensor.