P0136 OBD-II Trouble Code: O2 Sensor Circuit Malfunction (Bank 1, Sensor 2)

Our certified mechanics come to you · Get a fair and transparent estimate upfront

Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0136 code

P0136 is a diagnostic trouble code (DTC) for "O2 Sensor Circuit Malfunction (Bank 1, Sensor 2)". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$20.00
Toyota$20.00
BMW$20.00
SCHEDULE P0136 DIAGNOSTIC Get a fair and transparent estimate upfront

P0136 code definition

O2 Sensor Circuit Malfunction (Bank 1, Sensor 2)

What the P0136 code means

P0136 is the OBD-II generic code indicating the downstream O2 sensor for bank 1 fails to meet the minimum and maximum voltage limits calibrated for the ECM to see.

What causes the P0136 code?

  • The ECM monitors the O2 sensor’s highest and lowest voltages. This code occurs when the voltage limits are not within specifications programmed into the ECM.

  • The ECM detects a voltage problem and turns on the Check Engine Light.

  • The ECM uses other O2 sensors to try and control the fuel injection with known values.

  • There is an exhaust leak or catalyst failure in front of the sensor.

What are the symptoms of the P0136 code?

  • The engine may run excessively rich if the engine goes into open loop.

  • The engine may start to misfire if the spark plugs get fouled out over time.

  • The Check Engine Light will be illuminated.

  • You may have exhaust leaks or loss of power from a clogged or bad catalyst.

How does a mechanic diagnose the P0136 code?

  • Scans codes and documents freeze frame data then clear codes to verify failure

  • Monitors O2 sensor data to see if the voltage is switching back and forth between low and high at a fast rate compared to other sensors

  • Checks the O2 sensor wiring and the harness connections for any corrosion

  • Checks the O2 sensor heater circuit for the proper resistance to specifications

  • Checks for exhaust leaks before the sensor

  • Follow the manufacturer's specific pinpoint tests for further diagnosis.

Common mistakes when diagnosing the P0136 code

Follow these simple guidelines to prevent misdiagnosis:

  • Repair any exhaust leaks before the sensor to prevent incorrect readings.

  • Check the O2 sensor for oil or coolant contaminants from engine leaks.

  • Repair any harness that is damaged properly without taking shortcuts to prevent repeat failures.

  • Check the removed O2 sensor for damage from a defective catalyst and replace the catalyst if it is faulty.

How serious is the P0136 code?

  • The voltage output from the O2 sensor may point to engine and exhaust problems causing the O2 sensors to give erratic output voltages.

  • The O2 sensor may not read correct if the catalyst is damaged in front of the sensor.

  • The ECM may stay in open loop until the O2 system is repaired or the O2 sensor starts working again causing extended rich conditions that could possibly damage other engine components.

What repairs can fix the P0136 code?

Additional comments for consideration regarding the P0136 code

The O2 sensor circuit for bank 1 sensor 2 is used to give a voltage feedback to the ECM to control the fuel and provide information about catalyst operation.

Need help with a P0136 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

Check Engine Light
P0136
trouble codes

No more waiting rooms! Our mechanics will come to you to diagnose and fix the P0136 code.

SCHEDULE P0136 DIAGNOSTIC
Get a $20 credit for the follow-up repair

Recent Check Engine Light is on Inspection reviews

Excellent Rating

(6,328)

Rating Summary
5,857
225
52
35
159
5,857
225
52
35
159

Gustavo

17 years of experience
296 reviews
Gustavo
17 years of experience
Toyota Corolla - Check Engine Light is on - New Braunfels, Texas
As always, punctual and professional. He explains the problem thoroughly. I feel confident in his work and knowledge.

Greg

22 years of experience
86 reviews
Greg
22 years of experience
Mazda 3 - Check Engine Light is on - Queen Creek, Arizona
Greg was scheduled for 1:00 but he was able to come earlier and let us know right away. He was very thorough and spent his time going thru the entire car.

Gustavo

17 years of experience
296 reviews
Gustavo
17 years of experience
Lincoln Aviator - Check Engine Light is on - San Antonio, Texas
Made call before appt. -courteous-knowledgeable-got part need & did prompt repair after computer check.

Claud

8 years of experience
325 reviews
Claud
8 years of experience
Chevrolet Trax - Check Engine Light is on - Grosse Pointe, Michigan
Very good experience. He arrived on time. Explained what he was going to do. Completed the work and was thorough in what I needed for my next service in plain language vs car jargon. I'm a raving fan of Claud!


Related questions

Check engine light is on. O2 oxygen sencer p0136 also other codes all with o2 sencer. Replaced all 4 but still have engin light.

Hello, thank you for this. The P0136 diagnostic code stands for a circuit malfunction. This means the sensor is not giving any information to the computer and no signal is detected. There is no relay for the circuit. The best...

Codes p0136, P0141

Although these codes are both for the downstream O2 sensor, they are completely different. The first code, P0136, has to do with actual sensor performance. The second code, P0141, has to do with the sensor heater circuit performance. The...

My engine light turns on, and i went to autozone to diagnosis, and it's faulty o2 sensor. Would you be able to replace it?

If code P0136 sets the only way you can determine if the oxygen sensor has failed is to use an automotive scope to graphically depict the sensor output waveform (it will look roughly like a sine wave) and switching rate...

More related articles

P0416 OBD-II Trouble Code: Secondary Air Injection System Switching Valve B Circuit Open
P0416 means there is an issue with the secondary air injection system, likely due to icing inside the pump from a failed check valve.
P0286 OBD-II Trouble Code: Cylinder 9 Injector Circuit High
P0286 P0286 code definition When the P0286 code gets stored, it’s because the vehicle’s ECM has received a voltage reading from the fuel injector circuit that isn’t within the parameters designated by the manufacturer. The reading could have also come...
P3467 OBD-11 Trouble Code: Cylinder 9 Deactivation/Intake Valve Control Circuit Low
What What the P3467 code means The P3467 code indicates that your vehicle’s intake valve control circuit is low. What causes the P3467 code? There may be one or more causes for the P3467 code. One may be that...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com