2003 Chevrolet 1500 5.3L Engine P0141 and P0161 Fault Code Diagnosis
A few months ago, after performing a coolant flush on my 2003 Chevrolet 1500 with a 5.3L V8 engine, the vehicle began triggering fault codes P0141 and P0161. I have already replaced both the oxygen sensor (P0141) and the heater circuit sensor (P0161) twice—once with NTK sensors and once with Bosch sensors—but neither replacement has resolved the issue. The problem persists despite proper installation and testing. I am seeking advice on how to properly diagnose and fix this recurring issue. Any insights or troubleshooting steps would be greatly appreciated.
Begin by checking the electrical circuits and verify that the relevant fuses are intact, especially those related to the oxygen sensor heater circuits. A blown fuse or poor wiring connection could be causing intermittent readings. Also ensure proper ground connections and signal integrity. Good luck—please update with your findings so others can benefit from your experience.