Drive with caution — fix soon.
P0141 means the heater circuit in the rear oxygen sensor on Bank 1 isn't drawing the current the computer expects. The internal heater helps the sensor reach operating temperature quickly so it can monitor the catalytic converter sooner after start-up. The usual fix is a new sensor, though a blown fuse or damaged wiring can also cause it.
$150 – $450
Varies by vehicle and root cause.
Yes, it's usually safe short-term and you likely won't notice a difference. Fix it soon, mainly so you can pass emissions and the converter stays monitored.
Replacing the downstream oxygen sensor typically costs $150-$450 with labor. A blown fuse or simple wiring repair can be cheaper.
It's moderate. It rarely affects how the car drives, but it will fail an emissions test and should be repaired so the converter is properly monitored.
Yes. Both are oxygen sensor heater faults on Bank 1, but P0135 is the front sensor before the converter and P0141 is the rear sensor after it.