P0136 code meaning
O2 Sensor Circuit Bank 1 Sensor 2
Powertrain system Generic code P01xx codes Check engine light
What P0136 means
The oxygen sensor after the catalytic converter on bank 1 (sensor 2) is a switching sensor (about 0.1–0.9 V) used for converter monitoring and fine mixture trim. P0136 is the general circuit code, and its exact meaning varies by manufacturer. Ford sets it as 'no activity' in a functional check: if the sensor never swings beyond about 0.42/0.48 V despite rich and lean phases – if needed after forced enrichment and leaning – once per drive cycle. Opel/GM Europe set it if the average voltage stays outside 400–500 mV after 10 min of closed loop; older Bosch Motronic if it stays at 0 V for 200 s despite heating. GM North America does not use P0136. When it fails, the control module stops the downstream trim and cannot evaluate the converter; there is no limp mode.
P0136 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.3 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P0136
- Check engine light on (usually after two drive cycles)
- Catalyst monitor readiness not set
- Slightly higher consumption possible without downstream trim
Common causes of P0136
- Most likelyDownstream sensor aged or poisoned (stays in the middle band)
- PossibleSignal or ground wire open or high-resistance, connector corroded
- PossibleSensor heater failed (sensor stays cold)
- Less likelyExhaust leak ahead of the sensor
- Less likelyControl module or software
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank1 sensor2Oxygen sensor wiringCatalytic converter
What each part of P0136 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| 36 | The exact fault in that area. |
What to do next
- Note P0136 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0136
What does P0136 mean?
P0136 means "O2 Sensor Circuit Bank 1 Sensor 2". The oxygen sensor after the catalytic converter on bank 1 (sensor 2) is a switching sensor (about 0.1–0.9 V) used for converter monitoring and fine mixture trim. It is a generic code, so it means the same on every make.
Is it safe to drive with P0136?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P0136 fail an emissions test?
Yes, it can. P0136 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0136 to fix?
Difficulty: easy. A typical repair takes 0.3 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0136 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.