ITEM NAME:2Pc Upstream & Downstream O2 Oxygen Sensor For Chevrolet Cobalt Hhr Pontiac C1M1 2Pc Upstream & Downstream O2 Oxygen Sensor For Chevrolet Cobalt Hhr Pontiac C1M1 Position:Upstream and Downstream,Sensor 1 & Sensor 2 Fitment Type:Direct Replacement Replaces Part Number:234-4066 234-4342