Drive with caution — fix soon.
P0131 means the front (upstream) oxygen sensor on Bank 1 is sending a voltage that's too low, which the computer reads as a constantly lean exhaust. The cause might be the sensor itself, its wiring, or a real lean condition such as an air or vacuum leak. Because this sensor directly guides fuel delivery, fixing it restores smoother running and proper emissions.
$150 – $450
Varies by vehicle and root cause.
Yes, short-term driving is usually fine, though you might feel a rough idle or use a bit more fuel. Address it soon so a lean condition doesn't damage the catalytic converter.
Replacing the oxygen sensor typically costs $150-$450 including labor. If the cause is a vacuum leak or wiring, the price can vary depending on the repair.
It's moderate. The car stays drivable, but a persistent lean signal can hurt fuel economy and, over time, the catalytic converter.
Yes. An intake or vacuum leak adds extra air and creates a genuinely lean mixture, so a technician should check for leaks before simply replacing the sensor.