2000 3.1 Malibu P0140 cleared 1 day later shows P1040 pndg.

Question

Muffler, tail pipe, interim pipe & gasket replaced for emission test. Passed w/o replacing cat converter. Within 1 wk got MIL that card reader showed as P0140. Cleared & next day card reader showed P0140 pending. No MIL prior to e-test.

Answer 1

Hi there

This code is for the bank 1 O2 sensor, sensor #2. No activity detected. This can be the result of the sensor itself and doesn't always mean there is an issue with the exhaust. There could be a wiring issue on the signal wire from the sensor to the computer as well.