P0138 Hyundai Code - HO2S 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 Hyundai indicates HO2S 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 Hyundai Description
What are the Possible Causes of the DTC P0138 Hyundai?
- 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 Hyundai?
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 Hyundai 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 Hyundai Code
What does the OBDII code P0138 mean on a Hyundai?
P0138 indicates that the oxygen sensor (Bank 1, Sensor 2) has detected a voltage higher than the expected range, which may signify a problem with the sensor or the exhaust system.
What are the symptoms of code P0138 in a Hyundai?
Common symptoms include the check engine light turning on, poor fuel efficiency, rough idling, and sometimes a noticeable smell of fuel from the exhaust.
What causes the P0138 code to appear in a Hyundai?
Possible causes include a faulty downstream oxygen sensor (Bank 1, Sensor 2), damaged wiring or connectors, a rich fuel mixture, or issues with the catalytic converter.
Can a bad oxygen sensor cause code P0138 in my Hyundai?
Yes, a faulty or failing downstream oxygen sensor is one of the most common causes of the P0138 code.
How do I fix the P0138 code on a Hyundai?
Repairs may include replacing the downstream oxygen sensor, repairing wiring or connectors, inspecting and repairing the catalytic converter, or addressing fuel system issues causing a rich mixture.
Is it safe to drive my Hyundai with a P0138 code?
While the vehicle may still be drivable, it’s not recommended to ignore the code, as it can lead to decreased fuel efficiency, further damage to the catalytic converter, or increased emissions.
How can I diagnose the P0138 code in a Hyundai?
Start by scanning the OBDII system for codes, inspecting the Bank 1 Sensor 2 wiring and connectors for damage, testing the oxygen sensor's voltage, and checking for exhaust or fuel system issues.
What is the location of Bank 1 Sensor 2 in a Hyundai?
Bank 1 Sensor 2 is the downstream oxygen sensor located after the catalytic converter on the side of the engine with cylinder 1.
Can a vacuum leak cause the P0138 code on a Hyundai?
A vacuum leak is unlikely to directly cause P0138, but it may contribute to an incorrect air-fuel mixture, which could indirectly affect oxygen sensor readings.
How much does it cost to fix a P0138 code on a Hyundai?
Repair costs vary depending on the issue, but replacing the oxygen sensor typically costs $150 to $300, including parts and labor. Wiring or catalytic converter repairs may cost more.
Discuss the causes and fixes for P0138 Hyundai OBDII Code
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