AutoCodes – Pontiac – P1138 Pontiac

P1138 Pontiac Code - HO2S Bank 1 Sensor 2 Rich or High Voltage

Quick Answer

In order to control emissions, a catalytic converter converts any harmful exhaust emissions into harmless water vapor and carbon dioxide. Common causes include Faulty HO2S Bank 1 Sensor 2, HO2S Bank 1 Sensor 2 harness is open or shorted, HO2S Bank 1 Sensor 2 circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P1138 Pontiac indicates HO2S Bank 1 Sensor 2 Rich or High Voltage.
Common causes: Common causes include Faulty HO2S Bank 1 Sensor 2, HO2S Bank 1 Sensor 2 harness is open or shorted, HO2S Bank 1 Sensor 2 circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 4,545

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

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Table of contents Created and updated by William Orellana on Jul 12, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P1138 Pontiac Description

In order to control emissions, a catalytic converter converts any harmful exhaust emissions into harmless water vapor and carbon dioxide. The Powertrain Control Module (PCM) can monitor this process by using a rear Heated Oxygen Sensor 2 (HO2S 2). The HO2S 2, located in the exhaust stream past the catalytic converter, produces an output signal which indicates the storage capacity of the catalyst. This signal indicates the catalyst's ability to effectively convert the exhaust emissions. If the catalyst is functioning properly, the HO2S 2 signal will be far less active than the signal produced by the front Heated Oxygen Sensor 1 (HO2S 1).

OBDII Code P1138 Pontiac - HO2S Bank 1 Sensor 2 Rich or High Voltage - AutoCodes.com — P1138 Pontiac Code - HO2S Bank 1 Sensor 2 Rich or High Voltage

What does this mean?

What are the Possible Causes of the DTC P1138 Pontiac?

Faulty HO2S Bank 1 Sensor 2
HO2S Bank 1 Sensor 2 harness is open or shorted
HO2S Bank 1 Sensor 2 circuit poor electrical connection

How to Fix the DTC P1138 Pontiac?

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 P1138 Pontiac 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 P1138 Pontiac Code

What does the OBDII code P1138 mean for a Pontiac?

P1138 indicates that the downstream oxygen sensor (Bank 1, Sensor 2) is detecting a consistently rich fuel mixture or high voltage output.

What are common symptoms associated with the P1138 code in a Pontiac?

Symptoms may include poor fuel economy, a check engine light, rough idling, increased emissions, and reduced engine performance.

What causes the P1138 code to appear on a Pontiac?

Potential causes include a faulty oxygen sensor, damaged wiring or connectors, exhaust leaks, fuel system issues such as a leaking fuel injector, or a malfunctioning catalytic converter.

How can I diagnose the P1138 code on my Pontiac?

Start by inspecting the wiring and connectors for damage near the oxygen sensor, then test the sensor with a multimeter. Check for exhaust leaks and evaluate fuel system components for irregularities.

Can I drive my Pontiac with the P1138 code active?

Driving is possible, but itâ€™s not recommended as the issue may cause poor fuel efficiency, increased emissions, and potentially damage the catalytic converter over time.

How do I fix the P1138 code on my Pontiac?

Repairs may include replacing the oxygen sensor, repairing or replacing damaged wiring, addressing exhaust leaks, or fixing fuel system components like injectors.

How much does it cost to fix the P1138 code on a Pontiac?

Costs vary depending on the underlying issue. Replacing an oxygen sensor typically costs $100-$300, while fixing wiring or exhaust leaks may add to the expense.

Will replacing the HO2S Bank 1 Sensor 2 resolve the P1138 code?

If the sensor is faulty, replacing it may resolve the code. However, other issues such as wiring damage or exhaust leaks should be ruled out first.

Can a P1138 code cause long-term damage to my Pontiac?

Yes, if left unresolved, it can lead to catalytic converter damage, reduced engine performance, and increased fuel consumption over time.

How can I prevent P1138 from occurring again in my Pontiac?

Regular maintenance, ensuring proper fuel system function, checking for exhaust leaks, and replacing oxygen sensors at recommended intervals can help prevent this code.