P0146 Fault Code on 2000 Chevy S10 4.3L: Downstream O2 Sensor Issue?
We're experiencing a recurring P0146 diagnostic trouble code on our 2000 Chevrolet S10 with the 4.3L engine. We've already replaced both downstream oxygen (O2) sensors located on the exhaust pipes—driver's and passenger sides—and cleared the code, only for it to return approximately every three days. The fault specifically points to Bank 1 Sensor 3. Based on my understanding, this is not the upstream O2 sensor near the manifold, but rather a downstream sensor. Has anyone else encountered this issue on a 2000 Chevy S10 4.3L? Any insights or troubleshooting steps would be greatly appreciated.
Verify the O2 sensor circuit for continuity and proper wiring connections, especially since P0146 is often related to a faulty downstream sensor or ground issues.