P0171 Ford Code Causes And Fixes [Comprehensive Guide]

Are you encountering the P0171 Code on your Ford vehicle? Are you curious about its meaning and why it appears on your dash?

P0171 is a Diagnostic Trouble Code (DTC) that frequently appears in Ford vehicles and indicates the “System Too Lean (Bank 1).” In simple terms, the fuel mixture is too lean in the first bank of the engine; in other words, there is too much air but not enough fuel in the engine.

The proper understanding of this error message is crucial, as it can affect fuel efficiency, engine performance, and durability. This guide will cover the meanings of P0171 Ford, its causes, symptoms, and how to fix it.

What Is The P0171 Code?

When you encounter the P0171 engine code on your Ford vehicle, it signifies that the Onboard Diagnostic System (OBD-II) has detected a lean condition in Bank 1 of your engine. This means that the Powertrain Control Module (PCM) has determined there is an insufficient amount of fuel being delivered to the combustion chamber in that specific bank.

14.7:1 is the ideal/average ratio for the air-fuel mixture for combustion, but if the air-fuel ratio substantially departs from this ratio, leading to poor engine performance and other issues.

Common Causes Of P0171 Code In Ford

Various causes can trigger the error code P0171 Ford, and these causes can vary from very common to specific faults within systems. Here are some of the most common causes for the P0171 warning code in Ford vehicles:

Vacuum Leaks

Vacuum leaks are the most common issue that can lead to system lean conditions not only in Ford but all vehicles. Moreover, intake manifold gaskets, vacuum hoses, and PCV (Positive Crankcase Ventilation) Values are some sources for leaks that you can check.

Fuel Delivery Problems

Insufficient fuel delivery issues also can be the reason for a lean condition (Bank 1). This possibly can happen if the fuel injectors in your Ford are clogged or malfunctioning. However, weak fuel pumps, dirty or faulty fuel filters, and low fuel pressure are some key fuel system issues.

Exhaust Leaks

Exhaust leaks in the system may trigger the P0171 code and introduce fresh air that can lead to the O2 sensor falsely. So, ensure that there are no leaks in the exhaust system.

Clogged Fuel Injectors

Dirty or clogged fuel injectors also cause the error code P0171 Ford because they may not deliver enough fuel to the engine, and this thing can lead to a system that is too lean condition bank 1. However, make sure the injectors are clean and working in optimal condition.

Symptoms Of P0171 Code In Ford Vehicles

There are several symptoms that you can experience when the P0171 code displays on your Ford dashboard. However, based on the previous records and stats, here is the list of the most common symptoms of P0171:

Check engine light
Rough idling
Poor fuel economy
Lack of power
Engine misfires
Stalling

P0171 Ford: Fixes And Solutions

Before fixing the issues, it is important to disagree on the root cause of the problem and run a diagnosis test for that purpose. Once you find the exact location of the issue, you can follow the below producers for fixes. However, these procedures can depend on the root cause.

Fix Vacuum Leaks: If you have found a vacuum leak, you’ll need to change the affected hoses or gaskets.

Replace Fuel Pump or Injectors: If the report says the issue is with the fuel delivery system, then you’ve to replace that specific fuel pump or injector that is involved in the issue.

Clean or Replace the MAF Sensor: If the MAF sensor is found dirty, then ensure it’s cleaned by a specialized MAF sensor cleaner to fix the issue. But if the MAF sensor is damaged, then you’ll need to replace it.

Commonly Affected Ford Models by P0171 Code

Ford customers have experienced the p0171 code in various models, especially in high-mileage models. Therefore, here is a detailed list of the most commonly affected Ford models by P0171 Code:

Ford Escape
Ford F150
Ford Focus
Ford Explorer
Ford Mustang
Ford Fusion
Ford Edge
Ford Expedition
Ford Ranger
Ford Taurus
Ford Flex
Ford Fiesta
Ford Windstar
Ford Crown Victoria
Ford Transit Connect
Ford E-Series (E-150, E-250, E-350)

Repair Cost For P0171 Ford

For fixing systems to lean condition code P0171, the total repair cost can vary depending on the problem and the replacement of affected parts. However, you can assume that you will pay between $720 and $2100.

This is just an estimated cost, can be different, and includes all sub-services that fall in the P0171. Moreover, you can take your vehicle to a Ford specialized repair shop for the right costs. It is always best to discuss with a professional before taking any step.

In A Nutshell

The lean fuel condition can occur due to various issues such as vacuum leaks, exhaust leaks, fuel delivery problems, and clogged fuel injectors. These issues can further lead to poor vehicle performance and reduce fuel economy.

However, knowing these issues is not enough to resolve but can be a plus point for any Ford driver. After an in-depth understanding of the P0171 code, its symptoms, fixes, and costs, the driver can prevent his vehicle from potential problems before they encounter it.

FAQ’s – Frequently Asked Questions

What Does the P0171 code mean on a Ford?

P0171 code is a DTC, which means that Bank 1 of the engine is running in a lean condition. This error shows that there’s too much air but low fuel in the combustion.

Can I drive with the P0171 Ford code?

Driving with a P0171 error code on your Ford’s dash may cause poor engine performance and fuel efficiency and reduce the overall optimal vehicle’s performance. However, it’s not recommended at all to drive your vehicle along with the P0171 warning light.

What is the cost of fixing a P0171 code on a Ford?

The total cost for that service on a Ford ranges from $720 to $2,100 on average. This cost includes all the potential repairs like vacuum leaks, fuel pump O2 sensors, and MAF sensor replacement.

Which O2 sensor causes P0171?

The oxygen sensor engine bank 1 “upstream” is the sensor that triggers this issue. The oxygen sensor alerts the driver when the system finds the condition is too lean, indicating excessive oxygen levels in the exhaust.