AutoCodes – Toyota – P0136 Toyota RAV4

P0136 Toyota RAV4 Code - HO2S12 Circuit Malfunction

Quick Answer

The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: P0136 Toyota RAV4 indicates HO2S12 Circuit Malfunction.
Common causes: Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

Save to My Repairs Step-by-Step Diagnostic Guide My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 23,652

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0136 Toyota RAV4 Description

The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

OBDII Code P0136 Toyota RAV4 - HO2S12 Circuit Malfunction - AutoCodes.com — P0136 Toyota RAV4 Code - HO2S12 Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P0136 Toyota RAV4?

Faulty Rear Heated Oxygen Sensor Bank 1
Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

How to Fix the DTC P0136 Toyota RAV4?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

Replacing the Rear Heated Oxygen Sensor Bank 1 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0136 Toyota RAV4 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0136 Toyota RAV4 code?

Need more information on how to fix the P0136 Toyota RAV4 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0136 Toyota RAV4 code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0136 Toyota RAV4 Code

1. What does the OBDII code P0136 mean on a Toyota RAV4?

P0136 indicates a malfunction in the circuit of the downstream oxygen sensor (HO2S12), which is located after the catalytic converter.

2. What are the common symptoms of a P0136 code in a Toyota RAV4?

Symptoms may include the check engine light turning on, decreased fuel efficiency, and, in some cases, rough idling or poor engine performance.

3. What causes the P0136 code in a Toyota RAV4?

The most common causes are a faulty oxygen sensor, damaged wiring or connectors, exhaust leaks, or a malfunctioning PCM (Powertrain Control Module).

4. Can I drive my Toyota RAV4 with a P0136 code?

While the vehicle may still be drivable, prolonged driving with this code could lead to increased emissions, reduced fuel efficiency, or potential damage to other components like the catalytic converter.

5. How do I diagnose a P0136 code on a Toyota RAV4?

Start by inspecting the oxygen sensor and its wiring for damage. Use a multimeter to check for proper voltage and continuity, and perform an exhaust system inspection for leaks.

6. How do I fix the P0136 code on a Toyota RAV4?

Repairs may include replacing the downstream oxygen sensor, repairing damaged wiring or connectors, or fixing exhaust leaks. In rare cases, reprogramming or replacing the PCM may be necessary.

7. How much does it cost to fix the P0136 code on a Toyota RAV4?

The cost for replacing the downstream oxygen sensor typically ranges from $100 to $300, depending on parts and labor. Wiring repairs or other issues may vary in cost.

8. Can an exhaust leak trigger the P0136 code in a Toyota RAV4?

Yes, an exhaust leak near the downstream oxygen sensor can cause incorrect readings and trigger the P0136 code.

9. How can I prevent the P0136 code from recurring in my Toyota RAV4?

Regular maintenance of the exhaust system, ensuring connectors and wiring are secure, and replacing oxygen sensors as needed can help prevent this code.

10. Will a bad catalytic converter cause a P0136 code in a Toyota RAV4?

While uncommon, a failing catalytic converter can cause abnormal readings from the downstream oxygen sensor, potentially triggering the P0136 code.