How do you troubleshoot a P0171?

What repairs can fix the P0171 code?

Replacing the fuel pump.
Replacing the fuel filter.
Replacing the fuel pressure regulator.
Replacing the powertrain control module.
Replacing one or more injectors.
Replacing one or more oxygen sensors.
Replacing the mass air flow sensor.
Repairing a vacuum leak.

What to do if you have a p0171 lean code?

If you suspect a small vacuum leak causing your p0171 lean code, you can use a smoke machine to smoke check the intake manifold to help find the leak. A smoke machine is actually made to smoke the Evaporative Emissions system for leaks. However it works great for finding an air or a vacuum leak.

What does Bank 1 of p0171 mean?

Code P0171 Definition Bank 1 has too much air or not enough fuel. What Does P0171 Mean? Combustion engines run most efficiently when they maintain an air-fuel mixture ratio of 14.7 parts air to 1 part fuel.

What are the symptoms of check engine light p0171?

What Are The Symptoms Of P0171? 1 Check Engine Light is on 2 Lack of power from the engine 3 Rough idle 4 Engine coughing 5 Engine misfiring

When to run p0172 fuel trim system Lean?

If one of these sensors are off or “skewed”, the computer will run the engine either slightly rich or lean depending on how the sensor goes bad which will flag a P0172 Fuel Trim System Rich code (Bank 1). But again, this is just one side of it.

What are the symptoms of a p0171 leak?

What Is The Cause Of P0171? 1 Dirty or faulty mass airflow sensor 2 Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket. 3 Weak fuel pump 4 Clogged or dirty fuel injectors 5 Clogged fuel filter 6 Exhaust leak 7 Faulty oxygen sensor 8 Faulty air-fuel ratio sensor

What to do if check engine light code p0171 is triggered?

If check engine light code P0171 is triggered again, check the rest of the vacuum lines for leaks and continue to the rest of the diagnostic process. Remove the mass airflow sensor and clean the sensor using mass air flow cleaner or contact cleaner.