I an getting a P0131 on my 2000 Malibu. I checked wiring and connections and then disconected the battery for a minute to turn off the check engine light. I started the engine and the check engine light instantly came back on. I would think it would take ar least a couple minutes for the code to set again. What problem would that indicate?
2000 Malibu check engine light does not go out after disconecting the battery? on 2000 Chevrolet Malibu
The oxygen sensor has probably failed. This code refers to bank 1 sensor 1. Replace the sensor and reset again.
It sounds like the code did not clear the first time you disconnected the battery. Use a scan tool to clear it. The O2 Sensor diagnostic only runs during closed loop operation, and the PCM has to see less than 175mV for 50 seconds to be a failure. The PCM does not turn the Check Engine Light on the first failure either. It has to have 2 failures. A simple code reader may or may not have a "clear codes" function. Clear it for sure first before spending money on any attempted repairs.