P0138 2003 Toyota Highlander Code - Oxygen Sensor Circuit High Voltage Bank 1 Sensor 2
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 2003 Toyota Highlander indicates Oxygen Sensor Circuit High Voltage 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.
Code P0138 2003 Toyota Highlander Description
What are the Possible Causes of the DTC P0138 2003 Toyota Highlander?
- 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 2003 Toyota Highlander?
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 2003 Toyota Highlander 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 2003 Toyota Highlander Code
1. What are the common symptoms of OBDII code P0138 in a 2003 Toyota Highlander?
- Common symptoms of code P0138 include poor fuel economy, rough idling, or a noticeable decrease in engine performance.
2. What does the OBDII code P0138 "Oxygen Sensor Circuit High Voltage Bank 1 Sensor 2" mean for a 2003 Toyota Highlander?
- This code indicates that the oxygen sensor downstream of the catalytic converter in bank 1 is sending a signal indicating high voltage.
3. What are the possible causes of OBDII code P0138 in a 2003 Toyota Highlander?
- Possible causes of code P0138 include a faulty oxygen sensor, damaged wiring or connectors, exhaust leaks, or issues with the catalytic converter.
4. How can I diagnose the OBDII code P0138 in my 2003 Toyota Highlander?
- Diagnosing code P0138 typically involves checking the oxygen sensor's voltage readings, inspecting the sensor and its wiring for damage, and ensuring there are no exhaust leaks.
5. Can I still drive my 2003 Toyota Highlander with OBDII code P0138?
- It is generally not recommended to drive with code P0138 present, as it can lead to decreased fuel efficiency and potential damage to the catalytic converter over time.
6. How can I repair OBDII code P0138 in my 2003 Toyota Highlander?
- Repairing code P0138 may involve replacing the oxygen sensor in bank 1 sensor 2, repairing damaged wiring or connectors, fixing any exhaust leaks, or addressing catalytic converter issues.
7. Is it safe to reset the OBDII code P0138 in my 2003 Toyota Highlander using a diagnostic tool?
- While you can reset the code temporarily, it is important to address the underlying issue causing code P0138 to prevent it from reoccurring and potentially causing further damage to your vehicle.
8. How much does it cost to fix OBDII code P0138 in a 2003 Toyota Highlander?
- The cost of fixing code P0138 can vary depending on the specific issue causing the code, but it may range from a few hundred to a thousand dollars, including parts and labor.
9. Will OBDII code P0138 cause my 2003 Toyota Highlander to fail an emissions test?
- Yes, code P0138 can cause your vehicle to fail an emissions test due to its impact on the efficiency of the catalytic converter and the emission control system.
10. How often should I check the oxygen sensors in my 2003 Toyota Highlander to prevent OBDII code P0138?
- It is recommended to have your oxygen sensors inspected during routine maintenance or whenever you experience symptoms like poor fuel economy or engine performance to catch any issues early and prevent code P0138.
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