This means the air/fuel mixture in the engine's cylinders is too lean on Bank 1 (typically the side of the engine containing cylinder #1). A lean mixture has too much air and not enough fuel.
Several things can cause this:
* Vacuum Leaks: A leak in the intake manifold, vacuum hoses, or PCV system allows excess air to enter the engine, making the mixture lean. This is a very common cause of P0171.
* Mass Airflow Sensor (MAF) Issues: A faulty MAF sensor provides incorrect readings to the engine's computer, leading to a lean fuel mixture. It might be dirty, damaged, or failing.
* Fuel Injectors: Clogged or malfunctioning fuel injectors can prevent sufficient fuel from reaching the cylinders.
* Fuel Pump: A weak fuel pump may not deliver enough fuel pressure.
* Fuel Filter: A clogged fuel filter restricts fuel flow.
* Oxygen Sensor (O2 Sensor): A faulty O2 sensor can provide incorrect feedback to the engine's computer, leading to incorrect fuel adjustments. Bank 1 refers to the sensor on that side of the engine.
Troubleshooting Steps (in approximate order of likelihood and ease):
1. Check for Vacuum Leaks: Carefully inspect all vacuum hoses and connections for cracks, holes, or loose fittings. Listen for hissing sounds around the intake manifold.
2. Clean the MAF Sensor: Use MAF sensor cleaner (not carburetor cleaner) to carefully clean the sensor element. Avoid touching the sensor element with your fingers.
3. Inspect the Fuel Filter: If the filter is old or dirty, replace it.
4. Check Fuel Pressure: This requires a fuel pressure gauge and is best done by a mechanic.
5. Test the O2 Sensor (Bank 1): This usually requires a scan tool capable of live data monitoring. The O2 sensor should switch between lean and rich readings as expected. This is also usually best left to a mechanic.
6. Inspect Fuel Injectors: This often requires specialized tools and knowledge and is best handled by a mechanic.
Important Note: Simply clearing the code without addressing the underlying problem will only result in the code returning. Proper diagnosis is crucial to fix the issue permanently. While you can try the simpler steps yourself, it's advisable to take your Plymouth Breeze to a qualified mechanic for diagnosis and repair, especially if you're not comfortable working on your car's engine.
