P0031 and P0051 Error Codes - 2003 Nissan Altima 3.5 Fuel Sensor Issue After Battery Connection Mistake
I have a 2003 Nissan Altima 3.5 with persistent issues after replacing the alternator. During the replacement, I accidentally connected the battery while it was still disconnected, causing a spark that blew my main battery fuse on the positive cable. After replacing the fuse, the car runs poorly and struggles to stay running. It now shows error codes P0031 and P0051 related to oxygen sensors. I replaced the sensors as recommended, but the problem persists—especially when accelerating, where the engine dies unexpectedly. The vehicle is not holding a steady idle or maintaining power under load. What could be causing this? Are there any other components that should be checked besides the oxygen sensors?
The P0031 and P0051 codes indicate issues with the heater circuits for the oxygen sensors. These errors can often result from electrical faults or short circuits, especially after a battery connection error like yours. Check bbbind.com for detailed schematics of the heater circuit, including voltage levels and fuse locations to verify proper wiring and power supply.