P0171 - Fuel Injection System Too Lean Bank 1
Possible Causes:
- Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connection
P0174 - Fuel Injection System Too Lean Bank 2
Possible Causes:
- Intake air leaks
- Front Heated oxygen sensor may be faulty
- Injectors may be faulty
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Mass air flow sensor may be faulty
- Incorrect PCV hose connection
What Causes These Codes: Fuel injection system does not operate properly. The amount of mixture ratio compensation is too large. (The mixture ratio is too rich.) The Powertrain Control Module (PCM) monitors the engine Air/Fuel mixture
ratio, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio feedback signal
from the heated oxygen sensors 1. The PCM calculates the necessary
compensation to correct the offset between the actual and the
theoretical ratios.
In case the amount of the compensation value is extremely large (The
actual mixture ratio is too lean.), the PCM judges the condition as the
fuel injection system malfunction and light up the engine light. The codes is usually set when there is an intake leak after the air flow
meter, before replacing any parts check for loose or broken hoses and
intake gasket leak. On Ford some models dirty air filter, and dirty or
faulty air flow sensor are the cause of the problem.
Testimonial: "Thank you for such a fast turn a round. I will check for problems and now have a lace to start. Thank You again."
986 views
Usually answered in minutes!
×