What can cause a P0171?

What Is The Cause Of P0171?

  • Dirty or faulty mass airflow sensor.
  • Vacuum leaks – PCV hoses, vacuum hoses, intake manifold gasket.
  • Weak fuel pump.
  • Clogged or dirty fuel injectors.
  • Clogged fuel filter.
  • Exhaust leak.
  • Faulty oxygen sensor.
  • Faulty air-fuel ratio sensor.

Can a bad fuel pressure regulator cause a P0171 code?

A low fuel pressure will cause a deficient fuel delivery and as a consequence a possible code P0171. A bad fuel pressure regulator can be the culprit here, check out our article on the symptoms of a bad pressure regulator to learn more.

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.

How do I fix code P0171?

What repairs can fix the P0171 code?

  1. Replacing the fuel pump.
  2. Replacing the fuel filter.
  3. Replacing the fuel pressure regulator.
  4. Replacing the powertrain control module.
  5. Replacing one or more injectors.
  6. Replacing one or more oxygen sensors.
  7. Replacing the mass air flow sensor.
  8. Repairing a vacuum leak.

Can an exhaust leak cause a P0171 code?

An exhaust leak upstream of the O2 is kind of unlikely to cause a p0171, as it would have to be siphoning ‘clean’ air in via venturi effect. A head gasket leak or cracked head will allow the coolant to be burned. this will produce steam and free Ox that the O2 will pick up on.

Can a bad O2 sensor cause P0171?

What causes a p0171 code?

Causes of the P0171 code may include: A faulty fuel pressure regulator. A weak fuel pump. A clogged fuel filter. A faulty powertrain control module. A vacuum leak. Faulty injector(s)

How can I fix code p0171?

To fix the P0171 code, you need to check and repair vacuum leaks, repair low fuel pressure, or replace any faulty sensor that can cause a lean mixture on bank 1. What causes P0171 code? The most common causes of the P0171 code are vacuum or intake leaks, low fuel pressure, faulty PCV valve, or a faulty MAF sensor.

What does the Check Engine code po171 mean?

The P0171 code means that, on the first bank of the engine, the fuel system is running weak or a vacuum leak exists near this side of the engine. A lean condition occurs when the engine either receives too little fuel or too much air.

What are error codes p0171?

P0171 is a diagnostic trouble code (DTC) for “System Too Lean (Bank 1)”.