AutoCodes – Scion – P0139 2006 Scion xB

P0139 2006 Scion xB Code - Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2

Quick Answer

The rear Heated Oxygen (HO2) sensor (bank 1 sensor 2) is located behind the Three-Way Catalytic Converter (TWC) and detects the oxygen concentration in the exhaust gas. 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: P0139 2006 Scion xB indicates Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2.
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.

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Code Popularity 4,453

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 Mar 14, 2021

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0139 2006 Scion xB Description

The rear Heated Oxygen (HO2) sensor (bank 1 sensor 2) is located behind the Three-Way Catalytic Converter (TWC) and detects the oxygen concentration in the exhaust gas. For optimum TWC operation, the air-fuel mixture must be maintained as close as possible to the stoichiometric ratio. The HO2 sensor output voltage changes dramatically in the vicinity of the stoichiometric ratio. By making adjustments in accordance with these signal voltage changes, the ECM adjusts the fuel injection time so that the air-fuel ratio remains as close as possible to stoichiometric levels. The rear HO2 sensor generates a voltage that ranges from 0.1 V to 0.9 V according to the oxygen concentration in the exhaust gas. When the oxygen concentration in the exhaust gas increases, the HO2 sensor voltage drops below 0.45 V. The ECM interprets this as the air-fuel ratio is lean. Alternatively, the sensor voltage rises to more than 0.45 V when there is no oxygen in the exhaust gas. The ECM interprets this as the air-fuel ratio is rich.

OBDII Code P0139 2006 Scion xB - Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2 - AutoCodes.com — P0139 2006 Scion xB Code - Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0139 2006 Scion xB?

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 P0139 2006 Scion xB?

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 P0139 2006 Scion xB 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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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 P0139 2006 Scion xB Code

1. What are the common symptoms of OBDII code P0139 on a 2006 Scion xB?

- Common symptoms include poor fuel economy, rough idling, hesitation during acceleration, and an illuminated check engine light.

2. What does the OBDII code P0139 for a 2006 Scion xB indicate?

- This code indicates a slow response from the downstream oxygen sensor (Bank 1 Sensor 2) in the vehicle's exhaust system.

3. What are the possible causes of the Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2 code on a 2006 Scion xB?

- Possible causes include a faulty oxygen sensor, wiring or connector issues, exhaust leaks, engine misfires, or a damaged catalytic converter.

4. How can I diagnose the cause of OBDII code P0139 on my 2006 Scion xB?

- You can diagnose the issue by performing a visual inspection of the oxygen sensor and related components, checking for exhaust leaks, testing the sensor's voltage output, and scanning for any other trouble codes.

5. Can driving with OBDII code P0139 on a 2006 Scion xB cause further damage?

- Driving with this code may lead to decreased fuel efficiency and performance, and prolonged driving with a faulty oxygen sensor can potentially cause damage to the catalytic converter.

6. How can I repair OBDII code P0139 on my 2006 Scion xB?

- Repair options include replacing the downstream oxygen sensor, repairing any wiring or connector issues, fixing exhaust leaks, addressing engine misfires, or replacing a damaged catalytic converter.

7. Is it safe to continue driving my 2006 Scion xB with the Oxygen Sensor Circuit Slow Response Bank 1 Sensor 2 code?

- While the vehicle may still be operable, it is recommended to address the issue promptly to prevent further damage and ensure optimal performance and fuel efficiency.

8. Can I reset the check engine light after repairing OBDII code P0139 on my 2006 Scion xB?

- Yes, you can reset the check engine light using an OBDII scanner or by disconnecting the vehicle's battery for a few minutes. If the issue is properly resolved, the light should stay off.

9. How much does it typically cost to repair OBDII code P0139 on a 2006 Scion xB?

- The cost of repairs can vary depending on the exact cause of the issue and labor rates in your area. Replacing an oxygen sensor may cost around $100 to $300, while addressing more complex issues like a damaged catalytic converter can be more expensive.

10. Can I prevent OBDII code P0139 from recurring on my 2006 Scion xB in the future?

- Regular maintenance, such as keeping up with oil changes and spark plug replacements, can help prevent issues that may trigger this code. Additionally, addressing exhaust leaks promptly and using high-quality fuel can help maintain the health of the oxygen sensor and catalytic converter.