AutoCodes – Isuzu – P0140 Isuzu

P0140 Isuzu Code - HO2S Circuit High Voltage Sensor 2

Quick Answer

The heated oxygen sensor 2 (HO2S), 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: P0140 Isuzu indicates HO2S Circuit High Voltage 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 6,685

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 12, 2019

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0140 Isuzu Description

The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

OBDII Code P0140 Isuzu - HO2S Circuit High Voltage Sensor 2 - AutoCodes.com — P0140 Isuzu Code - HO2S Circuit High Voltage Sensor 2

What does this mean?

What are the Possible Causes of the DTC P0140 Isuzu?

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
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

How to Fix the DTC P0140 Isuzu?

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 does this mean?

Code Tech Notes

Replacing the Rear Heated Oxygen Sensor Bank 1 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0140 Isuzu 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 P0140 Isuzu code?

Need more information on how to fix the P0140 Isuzu code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0140 Isuzu 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 P0140 Isuzu Code

1. What are common symptoms of the OBDII code P0140 for the HO2S Circuit High Voltage Sensor 2 in an Isuzu?

- Common symptoms include poor fuel economy, rough idle, engine misfires, and the illumination of the Check Engine Light.

2. What are the possible causes of the P0140 code on an Isuzu related to the HO2S Circuit High Voltage Sensor 2?

- The code P0140 can be triggered by issues such as a faulty oxygen sensor, damaged wiring or connectors, exhaust leaks, or a malfunctioning engine control module.

3. How can I diagnose the P0140 code for the HO2S Circuit High Voltage Sensor 2 on my Isuzu?

- Diagnosing the P0140 code usually involves using an OBDII scanner to retrieve the code, checking the sensor's wiring and connectors for damage, and testing the sensor's voltage output.

4. Is it safe to continue driving my Isuzu with the P0140 code related to the HO2S Circuit High Voltage Sensor 2?

- It's generally not recommended to drive with the P0140 code present, as it can lead to poor engine performance and potential damage if left unresolved.

5. Can I repair the P0140 code for the HO2S Circuit High Voltage Sensor 2 on my Isuzu myself?

- Depending on your mechanical skills, you may be able to replace the oxygen sensor or repair damaged wiring yourself. However, more complex issues may require professional diagnosis and repair.

6. How much does it typically cost to repair the P0140 code for the HO2S Circuit High Voltage Sensor 2 on an Isuzu?

- The cost of repairing the P0140 code can vary depending on the exact cause of the issue, but it may range from $100 to $300 for parts and labor.

7. Are there any preventive measures I can take to avoid the P0140 code on my Isuzu related to the HO2S Circuit High Voltage Sensor 2?

- Regular maintenance checks, including monitoring your vehicle's oxygen sensors and addressing any engine issues promptly, can help prevent the occurrence of the P0140 code.

8. Will resetting the Check Engine Light clear the P0140 code for the HO2S Circuit High Voltage Sensor 2 on my Isuzu?

- Resetting the Check Engine Light may temporarily turn it off, but if the underlying issue causing the P0140 code is not addressed, the light is likely to come back on.

9. How long does it take to repair the P0140 code for the HO2S Circuit High Voltage Sensor 2 on an Isuzu?

- The repair time for the P0140 code can vary depending on the exact cause and complexity of the issue, but it may take anywhere from 1 to 3 hours for a professional mechanic to complete the repair.

10. Can the P0140 code for the HO2S Circuit High Voltage Sensor 2 on an Isuzu cause any long-term damage if not fixed?

- Ignoring the P0140 code can lead to decreased fuel efficiency, engine performance issues, and potential damage to the catalytic converter over time if not addressed promptly.