If your Honda Accord’s check engine light is on and the scanner shows code P1167, you’re likely looking for a clear explanation. What Does P1167 Honda Accord Trouble Code Mean? In simple terms, it points to an issue with the fuel-air mixture sensor in Bank 1, which is a critical component for your engine’s efficiency and performance.
This code is specific to Honda and Acura vehicles, so general OBD-II advice might not apply. It can cause symptoms like poor fuel economy, rough idling, or a lack of power. Understanding this code is the first step to getting your Accord running smoothly again.
What Does P1167 Honda Accord Trouble Code Mean?
The P1167 code is a manufacturer-specific diagnostic trouble code (DTC). In your Honda Accord, it stands for “Fuel Air Mix (FAM) Sensor Circuit Range/Performance Problem (Bank 1).” This sensor is also commonly called the Air-Fuel Ratio (AFR) sensor.
It’s located in the exhaust manifold on Bank 1 (the side of the engine with cylinder #1). Its job is to monitor the oxygen content in the exhaust gases after combustion. It sends this data to the engine control module (ECM), which uses it to constantly adjust the fuel injection for the perfect air-fuel mixture. When the ECM detects that the FAM sensor’s signal is outside the expected voltage range for too long, it triggers the P1167 code.
Common Symptoms of a P1167 Code
You might notice one or more of these signs before or after the check engine light appears:
* Illuminated Check Engine Light: This is the most common first sign.
* Poor Fuel Economy: You may find yourself visiting the gas station more often.
* Rough Idle or Stalling: The engine may shake or stumble when stopped.
* Lack of Power: The car might feel sluggish, especially during acceleration.
* Engine Hesitation: A noticeable pause or stumble when you press the gas pedal.
* Sometimes, No Symptoms: In some cases, the code may be stored without obvious drivability issues, but it should not be ignored.
Main Causes of the P1167 Code in Your Accord
Several issues can lead to this code. Here are the most frequent culprits, starting with the most likely:
1. A Faulty FAM/AFR Sensor: Over time, these sensors can simply wear out or become contaminated by oil ash or silicone, giving incorrect readings.
2. Exhaust Leaks: A leak in the exhaust manifold or a cracked pipe before the sensor can allow outside air in. This dilutes the exhaust gas, tricking the sensor into sending a lean signal.
3. Vacuum Leaks: Unmetered air entering the engine through a cracked hose, intake manifold gasket, or other vacuum line can disrupt the air-fuel mixture.
4. Fuel Delivery Problems: A weak fuel pump, clogged fuel filter, or dirty fuel injectors can cause a lean condition (too much air, not enough fuel).
5. Electrical Issues: Problems in the sensor’s wiring harness, such as damaged wires, loose connections, or corrosion, can interrupt the signal.
6. Faulty ECM: While rare, the engine computer itself could be malfunctioning.
How to Diagnose a P1167 Trouble Code
Diagnosis requires a systematic approach. You’ll need a quality OBD2 scanner and a basic set of mechanic’s tools. If you’re not comfortable, it’s best to consult a professional.
Step-by-Step Diagnostic Guide
Step 1: Scan and Record
Use your OBD2 scanner to confirm the P1167 code is present. Clear the code and take the car for a test drive. If it returns immediately, the problem is active. Note any other codes, as they can provide valuable clues.
Step 2: Perform a Visual Inspection
With the engine cool, visually inspect the following:
* FAM Sensor Wiring: Check the wiring harness connected to the FAM sensor (Bank 1) for any obvious damage, chafing, or burnt wires.
* Exhaust Manifold: Look for signs of soot or black carbon trails indicating an exhaust leak near the sensor.
* Vacuum Hoses: Inspect all vacuum lines, especially around the intake manifold, for cracks, brittleness, or disconnections.
Step 3: Check for Vacuum and Exhaust Leaks
A common and often overlooked cause is small leaks. You can listen for a hissing sound while the engine is running or use a can of carburetor cleaner. Be extremely careful. Spray small amounts around vacuum hoses and intake gaskets with the engine idling. If the engine RPM changes, you’ve found a leak. For exhaust leaks, listen for a ticking or puffing noise that increases with engine speed.
Step 4: Review Live Data with a Scanner
A advanced scanner that can read live data is crucial here. Look for the Bank 1 FAM or AFR sensor data.
* Watch the voltage. It should fluctuate rapidly between 2.8V and 3.2V (approximately) at idle.
* A sensor that is stuck high (lean signal), stuck low (rich signal), or has slow response time is likely bad.
* Compare it to the Bank 2 sensor (if your V6 Accord has one) – they should behave similarly.
Step 5: Test the Sensor and Circuit
If the live data suggests a problem, you can perform further electrical tests with a digital multimeter:
* Check the heater circuit resistance of the sensor (refer to a service manual for specs).
* Check for proper voltage supply and ground at the sensor connector.
If all wiring checks out and the live data is faulty, the sensor itself is the probable cause.
Repair Procedures for Code P1167
Once you’ve identified the likely cause, you can proceed with the fix.
Repair 1: Replacing the FAM/AFR Sensor
This is often the solution. Ensure you get the correct OEM or high-quality aftermarket part for your specific Accord year and engine.
1. Disconnect the negative battery terminal for safety.
2. Locate the Bank 1 FAM sensor on the exhaust manifold.
3. Disconnect the electrical connector.
4. Use an appropriate oxygen sensor socket and a breaker bar to carefully remove the old sensor. Penetrating oil can help if it’s rusty.
5. Install the new sensor, applying a small amount of anti-seize compound to the threads (most new sensors have this pre-applied). Avoid getting any on the sensor tip.
6. Reconnect the electrical plug and the battery.
7. Clear the codes and test drive.
Repair 2: Fixing Exhaust or Vacuum Leaks
Replace any cracked or damaged vacuum hoses. Fixing exhaust leaks may require replacing a gasket or having a manifold crack welded by a professional.
Repair 3: Addressing Fuel System Issues
If diagnostics point to a lean condition from fuel delivery, you may need to replace the fuel filter, clean injectors, or test fuel pressure.
Estimated Repair Costs
Costs can vary widely based on your location, the model year of your Accord, and whether you use OEM parts.
* DIY Sensor Replacement: The part alone for a FAM/AFR sensor typically ranges from $100 to $300. Your labor is free.
* Professional Repair: At a shop, you can expect total costs between $250 and $500+. This includes 1-2 hours of labor and the part mark-up.
* Additional Repairs: Fixing an exhaust manifold leak or a vacuum issue will add to the cost, potentially several hundred dollars more.
Can You Drive with a P1167 Code?
It’s not recommended to drive for an extended period with this code active. While the car may be drivable, the incorrect air-fuel mixture can lead to:
* Damage to the catalytic converter (a very expensive part) due to unburned fuel.
* Increased emissions.
* Poor performance and potential engine misfires over time.
* Reduced fuel economy costing you more at the pump.
Drive only as far as necessary to diagnose or repair the issue.
FAQs About the P1167 Code
Q: Is P1167 a serious code?
A: It is moderately serious. It won’t typically strand you, but ignoring it can lead to more expensive damage, especialy to the catalytic converter.
Q: What’s the difference between an O2 sensor and the FAM/AFR sensor?
A: The FAM/AFR sensor is a type of wideband oxygen sensor. It’s more precise and reacts faster than traditional upstream O2 sensors, providing a wider range of data for better fuel control.
Q: Can a dirty air filter cause P1167?
A: It’s not a direct cause, but a severely clogged air filter can restrict airflow and contribute to mixture problems. It’s a good, cheap thing to check and replace regularly.
Q: Will the code clear itself after I fix the problem?
A: Sometimes, after several drive cycles, the light may turn off if the problem is resolved. However, it’s best to clear the code with a scanner after the repair to confirm it doesn’t return.
Q: Can I use a generic O2 sensor to replace the FAM sensor?
A: No. You must use the correct Air-Fuel Ratio (AFR) or FAM sensor specified for your Honda Accord. A generic sensor will not funtion properly and will likely cause other codes.
Addressing a P1167 code promptly will help keep your Honda Accord running efficiently and reliably for many more miles. Always start with the simplest checks before assuming the sensor is bad, as leaks are a common and less expensive fix. If you’re ever in doubt, seeking help from a trusted mechanic is the best course of action.