AutoCodes – Generic – P0438

P0438 Code - Catalyst Temperature Sensor High Input Bank 2 Sensor 1

Quick Answer

The Engine Control Module (ECM) monitors the Catalyst Temperature Sensor Circuit Performance, which measures the temperature of the catalyst. Common causes include Faulty Catalyst Temperature Sensor, Catalyst Temperature Sensor harness is open or shorted, Catalyst Temperature Sensor 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: P0438 indicates Catalyst Temperature Sensor High Input Bank 2 Sensor 1.
Common causes: Common causes include Faulty Catalyst Temperature Sensor, Catalyst Temperature Sensor harness is open or shorted, Catalyst Temperature Sensor 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 25,076

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 Apr 18, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0438 Description

The Engine Control Module (ECM) monitors the Catalyst Temperature Sensor Circuit Performance, which measures the temperature of the catalyst. Catalyst Temperature Sensor function by increasing their resistance with increasing exhaust gas temperature. The ECM sets the OBDII code when the Catalyst Temperature Sensor signal is not to factory specifications.

OBDII Code P0438 - Catalyst Temperature Sensor High Input Bank 2 Sensor 1 - AutoCodes.com — P0438 Code - Catalyst Temperature Sensor High Input Bank 2 Sensor 1

What does this mean?

What are the Possible Causes of the DTC P0438?

Faulty Catalyst Temperature Sensor
Catalyst Temperature Sensor harness is open or shorted
Catalyst Temperature Sensor circuit poor electrical connection

How to Fix the DTC P0438?

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 is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0438 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.

Need more information about the P0438 code?

Need more information on how to fix the P0438 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0438 code diagnosed by a professional: Find a repair shop in your area

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 P0438 Code

1. What are the common symptoms of OBDII code P0438?

- Common symptoms include poor engine performance, decreased fuel efficiency, and the illumination of the check engine light.

2. What does the OBDII code P0438 indicate?

- P0438 indicates a high input from the catalyst temperature sensor located in Bank 2 Sensor 1 of the vehicle's exhaust system.

3. What are the possible causes of OBDII code P0438?

- The possible causes of P0438 include a faulty catalyst temperature sensor, wiring issues, a damaged sensor connector, or a malfunctioning PCM.

4. How can I diagnose the catalyst temperature sensor in Bank 2 Sensor 1?

- Use a multimeter to test the sensor's resistance and voltage output. Check the wiring and connector for any signs of damage or corrosion.

5. Can a dirty or failing catalytic converter trigger code P0438?

- Yes, a failing catalytic converter can cause the catalyst temperature sensor to read abnormally high temperatures, triggering code P0438.

6. How do I reset OBDII code P0438 after making repairs?

- Use an OBDII scanner to clear the code. If the issue has been successfully resolved, the check engine light should turn off.

7. Is it safe to continue driving with OBDII code P0438 present?

- It is generally not recommended to drive with a persistent check engine light, as it indicates a problem that could potentially affect the vehicle's performance and emissions.

8. Can I replace the catalyst temperature sensor myself?

- Replacing the sensor can be a straightforward DIY task for those with some mechanical experience. However, it's important to follow the manufacturer's guidelines and use the correct replacement part.

9. How much does it typically cost to repair OBDII code P0438?

- The cost of repairing P0438 can vary depending on the underlying issue. Replacing the catalyst temperature sensor may cost between $100 to $300, while fixing a damaged catalytic converter can be more expensive.

10. Will OBDII code P0438 cause my vehicle to fail an emissions test?

- Yes, code P0438 can cause your vehicle to fail an emissions test due to the potential impact on the efficiency of the catalytic converter and overall emissions control system.