P0138 2008 Nissan Pathfinder Code - HO2S12 Circuit High Voltage
Quick Answer
The Heated Oxygen Sensor 2 (HO2S) (Rear O2 Sensor), 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
- P0138 2008 Nissan Pathfinder indicates HO2S12 Circuit High Voltage.
- 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.
Code P0138 2008 Nissan Pathfinder Description
What are the Possible Causes of the DTC P0138 2008 Nissan Pathfinder?
- 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
- Intake air leaks
- Exhaust gas leaks
- Inappropriate fuel pressure
- Faulty fuel injectors
How to Fix the DTC P0138 2008 Nissan Pathfinder?
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 P0138 2008 Nissan Pathfinder 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 P0138 2008 Nissan Pathfinder Code
1. What does OBDII code P0138 mean on a 2008 Nissan Pathfinder?
P0138 indicates that the voltage from the downstream oxygen sensor (Bank 1, Sensor 2) is higher than expected, suggesting a potential issue with the sensor or exhaust system.
2. What are the common symptoms of code P0138 in a 2008 Nissan Pathfinder?
Symptoms may include the check engine light turning on, decreased fuel efficiency, rough idling, or a strong smell of fuel from the exhaust.
3. What causes the P0138 code to appear?
Common causes include a faulty downstream oxygen sensor, damaged wiring or connectors, a rich fuel mixture, or a malfunctioning catalytic converter.
4. Can a bad oxygen sensor trigger the P0138 code?
Yes, a failing or dirty downstream oxygen sensor is one of the most common reasons for this code.
5. How do I diagnose the P0138 code on a 2008 Nissan Pathfinder?
Start by checking the wiring and connectors for damage, use a multimeter to test the sensor voltage, and inspect the exhaust system for leaks or other issues.
6. Can a clogged catalytic converter cause the P0138 code?
Yes, a clogged or malfunctioning catalytic converter can lead to abnormal readings from the oxygen sensor, triggering the code.
7. Is it safe to drive with a P0138 code on my 2008 Nissan Pathfinder?
Driving with this code is generally not recommended, as it can lead to increased emissions, reduced fuel efficiency, and potential damage to the catalytic converter.
8. How do I fix the P0138 code on my 2008 Nissan Pathfinder?
Repairs may include replacing the downstream oxygen sensor, repairing damaged wiring, fixing exhaust leaks, or addressing issues with the catalytic converter.
9. How much does it cost to fix the P0138 code?
The repair cost can vary but typically ranges from $150 to $300 for an oxygen sensor replacement, depending on parts and labor costs.
10. Will clearing the P0138 code solve the problem?
Clearing the code will turn off the check engine light temporarily, but the underlying issue must be fixed to prevent the code from returning.
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