P0139 2016 Toyota RAV4 Code - Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2
Quick Answer
In order to obtain a high purification rate of the Carbon Monoxide (CO), Hydrocarbon (HC), and Nitrogen Oxide (NOx) components in the exhaust gas, a Three-Way Catalytic Converter (TWC) is used. Common causes include Faulty Oxygen Sensor Bank 1 Sensor 2, Oxygen Sensor Bank 1 Sensor 2 harness is open or shorted, Oxygen Sensor Bank 1 Sensor 2 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
- P0139 2016 Toyota RAV4 indicates Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2.
- Common causes
- Common causes include Faulty Oxygen Sensor Bank 1 Sensor 2, Oxygen Sensor Bank 1 Sensor 2 harness is open or shorted, Oxygen Sensor Bank 1 Sensor 2 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.
Code P0139 2016 Toyota RAV4 Description
The heated oxygen sensor is located behind the TWC and detects the oxygen concentration in the exhaust gas. Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low).
When the air-fuel ratio becomes lean, the oxygen concentration in the exhaust gas is high. The heated oxygen sensor informs the ECM that the post-TWC air-fuel ratio is lean (low voltage, i.e. less than 0.45 V).
Conversely, when the air-fuel ratio is richer than the stoichiometric air-fuel level, the oxygen concentration in the exhaust gas is low. The heated oxygen sensor informs the ECM that the post-TWC air-fuel ratio is rich (high voltage, i.e. more than 0.45 V). The heated oxygen sensor has the property of changing its output voltage drastically when the air-fuel ratio is close to the stoichiometric level.
The ECM uses the supplementary information from the heated oxygen sensor to determine whether the air-fuel ratio after the TWC is rich or lean and adjusts the fuel injection duration accordingly. Thus, if the heated oxygen sensor is working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the primary air-fuel ratio control.
The ECM continuously monitors the heated oxygen sensor output voltage while the engine is running. The sensor output voltage drops to below 0.2 V (extremely lean status) immediately when the vehicle decelerates, and the fuel cut is operating. If the voltage does not drop to below 0.2 V for 7 seconds or more, the ECM determines that the sensor response has deteriorated, illuminates the MIL, and stores a Diagnostic Trouble Code (DTC).
What are the Possible Causes of the DTC P0139 2016 Toyota RAV4?
- Faulty Oxygen Sensor Bank 1 Sensor 2
- Oxygen Sensor Bank 1 Sensor 2 harness is open or shorted
- Oxygen Sensor Bank 1 Sensor 2 circuit poor electrical connection
- Gas leak from exhaust system
How to Fix the DTC P0139 2016 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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0139 2016 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.
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Frequently Asked Questions about P0139 2016 Toyota RAV4 Code
What does the OBDII code P0139 mean for a 2016 Toyota RAV4?
P0139 indicates that the downstream oxygen sensor (Bank 1, Sensor 2) is taking too long to respond to changes in the air-fuel mixture, signaling a potential issue with the sensor or related components.
What are the common symptoms of a P0139 code in a 2016 Toyota RAV4?
Symptoms may include an illuminated check engine light, reduced fuel efficiency, rough idling, or increased emissions.
What causes the P0139 code to appear in a 2016 Toyota RAV4?
Common causes include a failing downstream oxygen sensor, exhaust leaks, a damaged sensor wiring harness, or excessive soot buildup on the sensor.
Can I drive my 2016 Toyota RAV4 with a P0139 code?
Driving with this code is usually safe in the short term, but ignoring it may lead to decreased fuel efficiency and potential damage to the catalytic converter.
How do I diagnose a P0139 code on a 2016 Toyota RAV4?
Diagnosis involves scanning for codes, inspecting the wiring and connectors for damage, checking for exhaust leaks, and testing the performance of the downstream oxygen sensor.
How do I fix the P0139 code on a 2016 Toyota RAV4?
Repairs may include replacing the downstream oxygen sensor, fixing exhaust leaks, cleaning the sensor, or repairing damaged wiring.
How much does it cost to fix a P0139 code on a 2016 Toyota RAV4?
Replacing the oxygen sensor typically costs between $150 and $300, depending on parts and labor. Additional repairs for wiring or exhaust leaks may increase costs.
Can a dirty air filter cause the P0139 code in a 2016 Toyota RAV4?
A dirty air filter is unlikely to directly cause P0139 but could contribute to poor engine performance, which may exacerbate sensor issues.
Will a P0139 code cause my 2016 Toyota RAV4 to fail an emissions test?
Yes, a P0139 code can cause your vehicle to fail an emissions test due to higher-than-normal emissions output.
How can I prevent the P0139 code from recurring in my 2016 Toyota RAV4?
Regular maintenance, such as replacing oxygen sensors as recommended, fixing exhaust leaks promptly, and using high-quality fuel, can reduce the likelihood of this code appearing.
Discuss the causes and fixes for P0139 2016 Toyota RAV4 OBDII Code
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