P0137

O2 Sensor Circuit Low Voltage Bank 1 Sensor 2

Fuel & air metering (emissions) Generic OBD-II Medium

What it means

P0137 means the downstream oxygen sensor (Bank 1, Sensor 2, after the catalytic converter) is reporting a steadily low voltage. That sensor checks how well the converter is working rather than trimming fuel, so the car usually drives fine — the practical effects are a check-engine light and a failed emissions test until the sensor, wiring, or a nearby exhaust leak is sorted out.

Medium

Can I keep driving? Yes, the car drives normally — this is a downstream O2 sensor code, so the main effects are a warning light and a failed emissions test.

Real-world scan data

Seen in

1,248

scans in the past year

Found in

0.2%

of scans

0.3%

of scans that found faults

Appears alongside · share of P0137 scans

P0420in 33.0% of scans

P0300in 32.2% of scans

P0138in 30.7% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Will fail an emissions/smog test
Little or no change in how the car drives
Possible slight drop in fuel economy

Common causes

Most likely first

Failed downstream (post-catalyst) oxygen sensorLikely
Exhaust leak near the sensor pulling in fresh air (false lean reading)Common
Wiring shorted to ground or a corroded connectorCommon
Open or high-resistance signal circuitLess often
Failed engine control module (rare)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and inspect the Bank 1 Sensor 2 connector and wiring for damage or corrosion.
Check for exhaust leaks upstream of the sensor, which can drive the voltage low.
Back-probe the sensor signal circuit for a short to ground or an open.
If wiring is good, replace the downstream O2 sensor.
Clear the code and drive a full cycle to confirm it stays off.

FAQ

Quick answers

Is it safe to drive with P0137?+

Yes. Sensor 2 monitors the catalytic converter rather than controlling fuel, so the car drives normally — but you'll fail emissions until it's fixed.

Can I just clear P0137?+

It will return once the sensor is monitored again unless the sensor, wiring, or exhaust leak causing the low voltage is repaired.

Read & clear P0137 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX