AutoCodes – Generic – P1086

P1086 Code - Fuel Control Mixture Rich Bank 2 Sensor 1

Quick Answer

To operate effectively, a gasoline engine requires a specific air-fuel ratio (lambda), with the theoretical ratio being 14.7:1. Common causes include Faulty Crankcase Ventilation Control Valve, Damage or loose Air Intake Tube, Faulty Mass Air Flow (MAF) sensor. 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: P1086 indicates Fuel Control Mixture Rich Bank 2 Sensor 1.
Common causes: Common causes include Faulty Crankcase Ventilation Control Valve, Damage or loose Air Intake Tube, Faulty Mass Air Flow (MAF) sensor.
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.

Save to My Repairs My Repairs

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

Code Popularity 10,204

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 18, 2023

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

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

Code P1086 Description

To operate effectively, a gasoline engine requires a specific air-fuel ratio (lambda), with the theoretical ratio being 14.7:1. However, different operating conditions, such as temperature or acceleration, necessitate a deviation from this ideal ratio, requiring adjustments through various facilities.
For maximum power output, a rich mixture is necessary during full-throttle operation. If lambda is less than 1, there is insufficient air, and the fuel-air mixture becomes rich. On the other hand, if lambda is greater than 1, there is excess air, and the mixture becomes lean, reducing fuel consumption and power output.
However, if lambda exceeds 1.3, the air-fuel mixture becomes difficult to ignite, and the engine no longer operates within safe limits. In practical applications, a lambda value of 0.9 to 1.1 has proven to be most favorable. If the engine needs to operate at a lambda value of 1, a fuel injection system with emission control will be necessary to ensure proper mixture preparation.
The electronic fuel injection system measures the engine's air intake and converts it into an electrical signal for evaluation by the DME control unit. Based on this signal and other parameters, the control unit calculates the fuel requirement and activates electromagnetic fuel injectors. These injectors intermittently inject fuel ahead of the cylinder inlet valves.

OBDII Code P1086 - Fuel Control Mixture Rich Bank 2 Sensor 1 - AutoCodes.com — P1086 Code - Fuel Control Mixture Rich Bank 2 Sensor 1

What does this mean?

What are the Possible Causes of the DTC P1086?

Faulty Crankcase Ventilation Control Valve
Damage or loose Air Intake Tube
Faulty Mass Air Flow (MAF) sensor
Faulty Ignition Coil(s)
Faulty Spark Plugs
Insufficient fuel pressure
Large vacuum leak on the engine

How to Fix the DTC P1086?

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 P1086 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 P1086 code?

Need more information on how to fix the P1086 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1086 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P1086 Audi — Exhaust Bank 4- Mixture Adaption Range 2 Lower Lean Limit Not Reached
P1086 BMW — Fuel Control Mixture Rich Bank 2 Sensor 1
P1086 MINI — Fuel Control Mixture Rich Bank 2 Sensor 1
P1086 Subaru — Tumble Generated Valve Position Circuit Low Sensor 2
P1086 Volkswagen — Exhaust Bank 4- Mixture Adaption Range 2 Lower Lean Limit Not Reached

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 P1086 Code

1. What are the common symptoms of OBDII code P1086?

The common symptoms of OBDII code P1086 include poor fuel economy, rough idle, engine misfires, and a strong smell of fuel from the exhaust.

2. What does the OBDII code P1086 Fuel Control Mixture Rich Bank 2 Sensor 1 indicate?

OBDII code P1086 indicates that the fuel mixture in Bank 2 Sensor 1 is too rich, meaning there is an excess of fuel compared to air in the combustion process.

3. What are the possible causes of OBDII code P1086?

Common causes of OBDII code P1086 include a faulty oxygen sensor, issues with the fuel injectors, a vacuum leak, a malfunctioning mass airflow sensor, or a problem with the fuel pressure regulator.

4. How can I diagnose the OBDII code P1086?

To diagnose OBDII code P1086, you can use an OBDII scanner to read the code and further investigate the oxygen sensor, fuel injectors, vacuum system, mass airflow sensor, and fuel pressure regulator for any signs of malfunction.

5. How can I repair OBDII code P1086?

Repairing OBDII code P1086 may involve replacing the oxygen sensor, cleaning or replacing the fuel injectors, fixing any vacuum leaks, replacing the mass airflow sensor, or repairing or replacing the fuel pressure regulator as needed.

6. Can driving with OBDII code P1086 cause further damage to the vehicle?

Continued driving with OBDII code P1086 can potentially lead to damage to the catalytic converter, reduced engine performance, and increased fuel consumption over time if left unresolved.

7. Is it safe to continue driving with OBDII code P1086?

While it may be safe to drive in the short term, it is recommended to address OBDII code P1086 promptly to prevent potential damage to the vehicle and ensure optimal engine performance and fuel efficiency.

8. How much does it typically cost to repair OBDII code P1086?

The cost of repairing OBDII code P1086 can vary depending on the specific cause of the issue, but it may range from a few hundred to over a thousand dollars, including parts and labor.

9. Can OBDII code P1086 be triggered by a loose gas cap?

While a loose gas cap can trigger a different code related to the evaporative emissions system, it is unlikely to directly cause OBDII code P1086 related to a rich fuel mixture in Bank 2 Sensor 1.

10. How often should I check for OBDII code P1086?

If you suspect an issue with your vehicle's fuel control system or experience symptoms related to a rich fuel mixture, it is recommended to check for OBDII code P1086 promptly to address any underlying problems.