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P0136 on Toyota RAV4

O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)

Factory diagnostic protocol and troubleshooting wire for fault code P0136 specifically for the Toyota RAV4 (2020–2026, 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP).

Verified OEM Telemetry & Field Repair Tree
Toyota RAV42020–2026
Toyota RAV4
SUV2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
RAV4 SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Low urgency level
Est. Repair Cost
$100 - $300 (DIY: $35 - $100)
Parts & Labor DIY
Check P0136 On Another Toyota Model:
Diagnose P0136 on Specific RAV4 Model Year:

1. Symptoms of P0136 on Toyota RAV4

When the Engine Control Module (ECM/PCM) on your Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP) logs fault code P0136, drivers commonly observe:

Illuminated Check Engine Light on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Failed state emissions test on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
No noticeable drivability degradation on Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP)
Toyota RAV4 OBD-II Port Location
The 16-pin diagnostic connector is located Driver footwell directly above brake pedal arm. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Toyota RAV4

Historical warranty claims and technical repair bulletins for Toyota RAV4 point to the following failure distribution:

55%
Failing downstream O2 sensor element (Toyota OEM Part)
25%
Corroded or road-damaged downstream sensor wiring underneath vehicle (Toyota OEM Part)
12%
Exhaust leak near downstream sensor bung (Toyota OEM Part)
8%
Faulty heater circuit inside the sensor (Toyota OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Toyota RAV4.

3. Step-by-Step DIY Repair Guide for Toyota RAV4

01
Inspect Downstream Sensor Wiring Under Car

Safely raise vehicle and inspect the wiring harness for Bank 1 Sensor 2 for road debris tears, contact with driveshaft, or heat damage. on the Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

Required Tool: Jack, Jack Stands, Flashlight
02
Test Sensor Heater Resistance

Unplug connector and measure resistance between the two heater wires (usually same color, e.g., black-black or white-white). Normal is 5–16 ohms. on the Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

Required Tool: Digital Multimeter
03
Replace Downstream Oxygen Sensor

Apply penetrating oil, unthread sensor with 22mm O2 socket, screw in new OEM sensor, reconnect weather-pack plug. on the Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

Required Tool: 22mm O2 Sensor Socket, Breaker Bar
04
Clear Trouble Codes & Complete Drive Cycle

Clear DTC memory and complete an OBD-II drive cycle to set catalyst and O2 monitors to 'Ready'. on the Toyota RAV4 equipped with 2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP.

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Toyota RAV4 (P0136)

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Direct-Fit Replacement Part

Toyota RAV4 OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Toyota RAV4.

$45 – $95 Prime
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Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
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Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for Toyota RAV4Verified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Toyota RAV4

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota RAV4:

4. Toyota RAV4 P0136 FAQs

What causes code P0136 to trigger on a Toyota RAV4?

On the Toyota RAV4 (2.5L 4-Cyl (A25A-FKS 203HP) / Hybrid AWD / Prime PHEV 302HP), P0136 is most frequently caused by Failing downstream O2 sensor element or Corroded or road-damaged downstream sensor wiring underneath vehicle.

Where is the OBD-II port located on my Toyota RAV4?

On the Toyota RAV4, the 16-pin DLC diagnostic connector is located Driver footwell directly above brake pedal arm. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Toyota RAV4 with code P0136?

Yes. Sensor 2 is downstream of the catalytic converter and monitors catalyst efficiency rather than air-fuel mixture. Given that P0136 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.