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P0137

O2 Sensor Low Voltage (Bank 1 Sensor 2)

The engine computer is seeing a very low signal from the oxygen sensor after the catalytic converter on Bank 1. This usually means the sensor, wiring, exhaust, or exhaust leak is causing the reading problem.

Severity3/5 Moderate
Can I drive?⚠ With caution

You can often drive short distances, but the problem should be diagnosed soon. Fuel economy and emissions may be affected, and an exhaust leak or wiring issue can get worse.

DIY
$20–$120
Shop
$120–$450
Difficulty
intermediate

What It Means

P0137 means the powertrain control module has detected low voltage from the Bank 1 Sensor 2 oxygen sensor circuit. This sensor is located after the catalytic converter and is used to monitor catalyst efficiency and exhaust oxygen content. A low-voltage condition can be caused by a failed sensor, damaged wiring, a poor connection, or an exhaust leak affecting the sensor reading.

Symptoms

Common Causes

1. Faulty downstream oxygen sensor (Bank 1 Sensor 2)high
2. Damaged, corroded, or loose wiring/connectors to the oxygen sensorhigh
3. Exhaust leak near the sensor or in the exhaust systemmedium
4. Blown fuse, heater circuit problem, or power/ground issue for the sensormedium
5. PCM issue or incorrect PCM inputlow

Related Codes

FAQ

Is P0137 the same as a bad catalytic converter?

Not usually. P0137 points to a low-voltage problem in the downstream oxygen sensor circuit, though a leak or exhaust issue can affect readings.

Can a bad oxygen sensor cause poor fuel economy?

Yes. If the sensor signal is wrong, the engine computer may adjust fueling incorrectly and reduce fuel economy.

Will clearing the code fix P0137?

No. The code will usually come back if the underlying sensor, wiring, or exhaust problem is not repaired.

Where is Bank 1 Sensor 2 located?

It is the oxygen sensor after the catalytic converter on the Bank 1 side of the engine.