1999 Malibu 3.1L Engine Multiple Fault Codes: PO101, PO131, PO137, PO300, P1133 - Diagnosis and Fixes
I plan to clean the Mass Air Flow (MAF) sensor to resolve the PO101 and P113-3 fault codes related to airflow detection. The vehicle has 120,000 miles and may still have original spark plugs. I intend to replace the spark plugs and inspect/replace plug wires if necessary to address the random misfire indicated by code PO300. I also hope that these repairs will resolve the oxygen sensor bank 1 sensor 1 and 2 low voltage faults (PO131 and PO137). If not, I am open to further suggestions before replacing the oxygen sensors. Any insights or recommendations on diagnosing or clearing these codes would be greatly appreciated.
Ensure your O2 sensor scanner can monitor live data from the oxygen sensors. Additionally, inspect all wiring and electrical connections to the O2 sensors for corrosion, damage, or loose terminals.