2PCS Upstream&Downstream Fits Pontiac GMC Isuzu Buick Oxygen O2 Lambda Sensor

Part Description

This oxygen sensor set includes both upstream and downstream units, referenced to OE 12578624. The sensors fit select Pontiac, GMC, Isuzu, and Buick platforms that share this GM-family O2 sensor specification.Upstream sensors mount before the catalytic converter to monitor exhaust oxygen for fuel trim adjustment, while downstream sensors sit after the cat to monitor converter efficiency. If your check engine light is throwing O2-related codes, this set covers both positions in one purchase.Use OE 12578624 to cross-check against your VIN, service records, or existing inventory before ordering. Product photos show the connector style, thread size, and harness length — compare them against the sensors you're pulling off the vehicle. If the specs match, submit an RFQ for pricing and availability.