P1156 Code - HO2S Rich Average Bank 2 Sensor 1
Quick Answer
P1156 indicates HO2S Rich Average Bank 2 Sensor 1. Common causes include Faulty O2 Sensor Heater Bank 2 Sensor 1, O2 Sensor Heater Bank 2 Sensor 1 harness is open or shorted, O2 Sensor Heater Bank 2 Sensor 1 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
- P1156 indicates HO2S Rich Average Bank 2 Sensor 1.
- Common causes
- Common causes include Faulty O2 Sensor Heater Bank 2 Sensor 1, O2 Sensor Heater Bank 2 Sensor 1 harness is open or shorted, O2 Sensor Heater Bank 2 Sensor 1 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.
Code P1156 Description
What are the Possible Causes of the DTC P1156?
- Faulty O2 Sensor Heater Bank 2 Sensor 1
- O2 Sensor Heater Bank 2 Sensor 1 harness is open or shorted
- O2 Sensor Heater Bank 2 Sensor 1 circuit poor electrical connection
How to Fix the DTC P1156?
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 P1156 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 P1156 code?
Need more information on how to fix the P1156 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P1156 code diagnosed by a professional: Find a repair shop in your area
Information for Specific Makes
- P1156 Audi — Manifold Absolute Pressure Sensor Open/Short To Ground
- P1156 BMW — O2 Sensor Heater Circuit Low Voltage Bank 2 Sensor 2
- P1156 Buick — HO2S Rich Average Bank 2 Sensor 1
- P1156 Cadillac — HO2S Rich Average Bank 2 Sensor 1
- P1156 Chevrolet — HO2S Rich Average Bank 2 Sensor 1
- P1156 Chrysler — Fuel Rail Pressure Malfunction Plausibility
- P1156 Ford — Fuel Selector Switch Circuit
- P1156 GMC — HO2S Rich Mean Bank 2 Sensor 1
- P1156 MINI — O2 Sensor Heater Circuit Low Voltage Bank 2 Sensor 2
- P1156 Volkswagen — Manifold Absolute Pressure Sensor Open/Short To Ground
Frequently Asked Questions about P1156 Code
What does OBDII code P1156 mean?
P1156 indicates that the upstream oxygen sensor (Bank 2, Sensor 1) is detecting a consistently rich air-fuel mixture on Bank 2.
What are the symptoms of code P1156?
Symptoms include poor fuel economy, rough engine idle, decreased performance, and possibly an illuminated Check Engine Light.
What causes code P1156?
Common causes include a faulty oxygen sensor, fuel injector issues, intake manifold leaks, or problems with the engine control module (ECM).
Can I drive with code P1156?
Driving with P1156 is possible but not recommended, as it may cause damage to the catalytic converter and worsen fuel efficiency.
How do I fix code P1156?
Repairs may involve replacing the oxygen sensor, inspecting for vacuum leaks, checking fuel injectors, or updating the ECM software.
How do I diagnose code P1156?
Start by scanning the vehicle with an OBDII scanner, inspecting the oxygen sensor wiring, checking for exhaust leaks, and testing fuel system components.
Is replacing the oxygen sensor always necessary for P1156?
No, replacing the oxygen sensor may not always be required; thoroughly diagnose the issue to rule out other causes like fuel system or exhaust leaks.
What is the cost to repair code P1156?
Repair costs vary, but replacing an oxygen sensor typically ranges from $150 to $400, while fuel system or ECM repairs may be more expensive.
Can a dirty air filter cause code P1156?
A dirty air filter is unlikely to directly cause P1156 but may contribute to an improper air-fuel mixture over time.
Does P1156 affect emissions?
Yes, P1156 can negatively affect emissions by increasing unburned fuel in the exhaust, potentially leading to a failed emissions test.
Discuss the causes and fixes for P1156 OBDII Code
Code P1156 comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
