What causes a lean mixture on the p0171 code?

Intake leaks are a widespread problem when it comes to the P0171 code. Intake/Vacuum/boost pipe leaks can trick the MAF sensor and cause a lean mixture. The MAF sensor measures all air that is going into the engine and telling the engine control unit which amount of air it is.

Can a faulty MAF sensor cause a p0171 code?

If you start replacing MAF sensors, O2 sensors, etc., you will probably spend a lot of money without results. A faulty O2 sensor is not a very common cause of the P0171 code, even if many people start to replace it directly when they see this code. Diagnosing the P0171 code is easy if you have the right tools to do it.

What does the p0171 code on an OBD2 mean?

P0171 OBD2 Trouble Code: System Too Lean (Bank 1) A P0171 code appears in the engine control unit when the Oxygen sensor on bank 1 recognizes a too lean air-fuel mixture for the sensor to correct it. Several different things could cause this trouble code. Here is what you need to know about the P0171 code.

What’s the problem with Nissan Maxima code p0171?

A Nissan TSB for Nissan Maxima dated March 2004 mentions replacing an air/fuel sensor as a solution for the code P0171. Another Ford TSB for a number of late 90-s Ford vehicles describes a problem with MAF sensor contamination where both codes, P0171 and P0174 would appear together.

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.

What does the p0171 code on bank 1 mean?

Code Definition. P0171 – System Too Lean (Bank 1) What does the P0171 code mean? The P0171 code means that the Oxygen (O2) sensor on bank 1 recognized a too lean mixture to correct it. The Oxygen O2 sensors have the ability to correct a fuel mixture of +-15%. If it needs to correct the air-fuel mixture more than that, the P0171 code will be stored.

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

When does the front O2 sensor Register p0171?

P0171 is triggered when the front O2 sensors recognize a lean mixture. It can both be a short-term lean mixture or a long-term lean mixture. If it’s a short-term lean mixture the fuel mixture is often very lean. If it’s a long-term mixture, it can register the code because of a small notice of lean mixture over time.

What does the OBDII trouble code p0171 mean?

The OBDII trouble code P0171 – System Too Lean (Bank 1)means that the engine air-fuel mixture is too lean, or there is too much air and too little fuel. Driving a car with the code P0171 can cause more damage to the engine over time, as when the engine runs lean, the combustion temperature is higher.

What causes the code p0171 on 2002 Toyota Corolla?

Q: What could cause the code P0171 on 2002 Toyota Corolla? A: In the 2002 Corolla, the code P0171 is often caused by a bad or dirty mass airflow sensor or vacuum leaks. Your mechanic can check for vacuum leaks and test the mass airflow sensor with a scan tool.

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.

Why is p0174 system too lean Bank 2?

P0174: System Too Lean Bank 2. PCM’s Adaptive Fuel Strategy has reached its rich calibrated limit for bank 2. In plain English, this means that the PCM has detected a vacuum leak (it may be real or perceived) and is compensating by injecting the maximum amount allowed (under its program) of fuel into the cylinders for bank 2.

What does code p0171-system too lean mean?

Code P0171 – System Too Lean: Symptoms, causes, common problems, diagnostic. The OBDII trouble code P0171 – System Too Lean (Bank 1) means that the engine air-fuel mixture is too lean, or there is too much air and too little fuel.

What does p0171 mean on a fuel mixture?

If it’s a short-term lean mixture the fuel mixture is often very lean. If it’s a long-term mixture, it can register the code because of a small notice of lean mixture over time. The P0171 code means that the front O2 sensors have recognized a lean mixture. The front O2 sensors are adjusting the fuel mixture that is coming out from the engine.

What causes p0171 code on Ford F-150?

For example, a P0171 on your Chevy Cruze could be due to a failing PCV system, while the P0171 on your friend’s Ford F-150 could be from a clogged fuel injector. Poor fuel mixture is a serious problem that major manufacturers face.

What does p0171 and po174 mean?

A continual low voltage reading indicates a lean fuel mixture, too much oxygen. The optimal ratio is 14.7:1 (air:fuel). When your powertrain/engine control module receives a reading that indicates there’s too much oxygen and the ratio is incorrect, it sends an error code P0171 or P0174.

What does the lean condition code p0171 mean?

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. When there are more than 14.7 parts air to 1 part fuel in the air-fuel mixture, a lean condition exists and code P0171 is triggered.