P0136

O2 Sensor Circuit Bank 1 Sensor 2

Oxygen sensor (O2) Generic OBD-II Medium

What it means

P0136 means the engine computer has detected a circuit problem with the downstream oxygen sensor (bank 1, sensor 2), located after the catalytic converter. This sensor monitors converter efficiency rather than controlling fuel, so the car usually drives normally — but the code keeps the check-engine light on and can block emissions readiness.

Medium

Can I keep driving? Yes — a rear O2 sensor fault doesn't usually affect driving; fix it to clear the light and let emissions monitors complete.

Real-world scan data

Seen in

2,374

scans in the past year

Found in

0.4%

of scans

0.7%

of scans that found faults

Appears alongside · share of P0136 scans

P0420in 42.5% of scans

P0300in 37.8% of scans

P0302in 37.5% 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
Emissions readiness monitor won't complete or fails an emissions test
Occasionally a slight change in fuel economy

Common causes

Most likely first

Failed or aged downstream oxygen sensor (bank 1, sensor 2)Likely
Wiring or connector fault at the sensor (heat or corrosion damage)Common
Exhaust leak near the sensorCommon
Failed ECM (rare)Less often

How to diagnose & fix

Work through it in order

Read the sensor 2 live signal to confirm it is inactive or out of range.
Inspect the sensor's wiring and connector, and check the exhaust for leaks near the sensor.
Check the sensor heater circuit if the signal never warms up.
Replace the downstream O2 sensor if it has failed.
Only consider the ECM after wiring and sensor checks pass.

FAQ

Quick answers

Is it safe to drive with P0136?+

Yes. The rear O2 sensor monitors catalytic-converter efficiency rather than controlling fuel, so driving is normally unaffected. The main issue is the check-engine light and blocked emissions readiness.

Can I just clear P0136?+

It will return once the ECM re-checks the sensor. The sensor or its wiring needs repair to keep the code from coming back.

Read & clear P0136 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