What causes P0171 and P0174 codes Ford?
What causes P0171 and P0174 codes Ford?
COMMON CAUSE: A DIRTY MAF SENSOR One of the most common causes of Ford P0171 and P0174 lean codes is a dirty mass airflow (MAF) sensor. The MAF sensor can also be contaminated by fuel vapors that back up through the intake manifold and throttle body when the engine is shut off.
How do I fix System Too Lean Bank 2?
Solutions: How to Fix a Lean Condition
- Inspect and Clean MAF Sensor.
- Check and Replace Air Filter.
- Repair Intake System Leaks after MAF Sensor.
- Replace O2 Sensors.
- Replace Fuel Pump and Injectors.
Can a bad 02 sensor cause a lean code?
So, an oxygen sensor failure can lead to incorrect readings of exhaust gasses. As a result, the faulty sensor can cause, a too rich or too lean condition. Any fuel that leaves the combustion chamber unburned; will enter the exhaust system and light-off when it reaches the catalytic converter.
How do you fix P0171 and P0174?
A common source of trouble code P0171 or P0174 is a dirty or failing MAF sensor….To clean the throttle body:
- Disconnect the air cleaner assembly from the throttle body.
- Spray some carburetor cleaner on a clean shop rag.
- Use the rag to clean around the throttle body and valve.
Can a bad o2 sensor cause a P0171?
Additional Causes of Code P0171 A plugged Fuel Filter or poorly functioning Fuel Pump can set the P0171 code. The computer hears (accurately) from the Oxygen Sensor that the Fuel Mixture is too lean so the computer keeps increasing the amount of fuel being delivered into the combustion chambers.
What causes fuel mixture too rich?
A faulty oxygen sensor sending the wrong signal to the engine control module can result in a rich fuel condition. Symptoms of a rich fuel condition include black colored exhaust, fouled spark plugs, and poor engine performance.
What happens if a car runs too rich?
When a car is running rich, it means the engine is receiving too much fuel and too little air. Your car will still crank and drive if it’s running rich, but you’ll likely experience symptoms like low gas mileage, slow acceleration and strong smell of gasoline (especially when idling).
Can bad spark plugs cause a rich condition?
Due to the spark needed to light the air/fuel mixture either being weak in spark or missing cycles completely. The gas starts to build in the cylinder every time it misfires or misses. So all the excess is blown out of the exhaust. Causing it to smell rich with the extra gas exiting the exhaust.