How to Fix P0171 Code on Ford F-150

How to Fix P0171

The P0171 code on your 2018 Ford F-150 indicates a lean condition in bank 1 of the engine. This means the engine is receiving too much air or not enough fuel. While many factors can trigger this code, owners of the 2018 Ford F-150 have reported that the PCV valve is a common culprit. As one owner reported: "After chasing P0171 for months, finally found the culprit - bad PCV valve causing a vacuum leak. $25 part, 30 minutes to replace." (source) This guide focuses on diagnosing and fixing the P0171 code by addressing PCV valve issues specific to the 2018 F-150.

Symptoms

The most common symptom associated with the P0171 code is the check engine light illuminating on your 2018 Ford F-150's dashboard. You may also notice some performance issues, although these can be subtle.

Some owners have reported a rough idle or hesitation during acceleration. Your truck might feel slightly underpowered, especially when climbing hills or carrying a load. These symptoms are often intermittent, making diagnosis challenging.

A vacuum leak is often associated with the P0171 code on this vehicle. If the PCV valve is the source of the problem, it's allowing unmetered air into the engine, disrupting the air/fuel mixture. This lean condition is what triggers the P0171 code. You might hear a hissing sound coming from the engine bay, which could indicate a vacuum leak.

In severe cases, you might experience stalling or difficulty starting the engine. However, these symptoms are less common with a simple PCV valve issue. The check engine light is the most reliable indicator that something is wrong.

Most Likely Cause

Based on owner reports, the most likely cause of a P0171 code on your 2018 Ford F-150 is a faulty PCV valve. The PCV (Positive Crankcase Ventilation) valve is a crucial component in your engine's emissions system. Its function is to regulate the pressure inside the crankcase by venting blow-by gases (combustion gases that leak past the piston rings) back into the intake manifold to be burned.

When the PCV valve fails, it can stick open or become damaged, creating a vacuum leak. This allows unmetered air to enter the intake manifold, leaning out the air/fuel mixture. The engine's computer (PCM) detects this lean condition through the oxygen sensors and triggers the P0171 code. This is why replacing the PCV valve often resolves the issue.

The 2018 Ford F-150's 5.0L engine seems to be particularly susceptible to PCV valve issues, although other engines can also be affected. Regular maintenance and inspection of the PCV valve can help prevent this problem from occurring. If you're experiencing the P0171 code, the PCV valve should be one of the first components you check.

How to Diagnose

Diagnosing a P0171 code related to the PCV valve involves a systematic approach. Here's a step-by-step guide to help you pinpoint the problem on your 2018 Ford F-150.

1. Read the Code: Use an OBD-II scanner to confirm the P0171 code. This is the first step to ensure you are addressing the correct problem.

2. Inspect the PCV Valve: Locate the PCV valve on your 2018 Ford F-150's engine. On the 5.0L engine, it's often integrated into the valve cover. Check for any visible signs of damage, such as cracks or breaks in the valve or its connecting hoses.

3. Check for Vacuum Leaks: With the engine running, listen for any hissing sounds around the PCV valve and its hoses. A vacuum leak can indicate a faulty valve or a damaged hose. You can use a stethoscope or a piece of hose to help pinpoint the location of the leak.

4. PCV Valve Test: With the engine idling, remove the PCV valve from its grommet. Place your finger over the valve opening. You should feel a strong vacuum. If there's little or no vacuum, the PCV valve is likely faulty or there is a blockage in the system.

5. Inspect PCV Hose: Carefully inspect the hose connected to the PCV valve for cracks, kinks, or looseness. Any of these issues can cause a vacuum leak and trigger the P0171 code. Replace the hose if you find any damage.

6. Check Valve Cover: Some owners of the 2018 Ford F-150 have found that the PCV valve is integrated into the valve cover, meaning you may need to replace the entire valve cover if the PCV valve is faulty. Inspect the valve cover for cracks or leaks around the PCV valve.

7. Clear the Code and Retest: After inspecting and potentially replacing the PCV valve, clear the P0171 code using your OBD-II scanner. Drive the vehicle for a while to see if the code returns. If the code does not return, the PCV valve was likely the culprit.

Tool Requirements:

• OBD-II scanner
• Socket set
• Screwdrivers
• Pliers
• Stethoscope (optional)

Step-by-Step Fix

Replacing the PCV valve on your 2018 Ford F-150 can often resolve the P0171 code. Here's a step-by-step guide to help you through the process.

1. Gather Your Tools and Parts: Make sure you have a new PCV valve (or valve cover, if necessary), socket set, screwdrivers, pliers, and potentially a new PCV hose.

2. Locate the PCV Valve: Find the PCV valve on your engine. As mentioned before, on some 2018 Ford F-150 models with the 5.0L engine, the PCV valve is integrated into the valve cover.

3. Disconnect the PCV Hose: Carefully disconnect the hose connected to the PCV valve. Use pliers if necessary, but be careful not to damage the hose.

4. Remove the Old PCV Valve: Depending on the design, the PCV valve may be threaded or simply pushed into a rubber grommet. If threaded, use a socket or wrench to unscrew it. If it's a push-in type, gently pull it out.

5. Inspect the Grommet (If Applicable): If the PCV valve is held in place by a rubber grommet, inspect it for cracks or damage. Replace the grommet if necessary to ensure a good seal.

6. Install the New PCV Valve: Install the new PCV valve in the reverse order of removal. If it's threaded, tighten it to the manufacturer's specified torque. If it's a push-in type, firmly press it into the grommet until it's securely seated.

7. Reattach the PCV Hose: Reconnect the PCV hose to the new PCV valve. Ensure the hose is securely attached and that there are no kinks or leaks.

8. Replace the Valve Cover (If Necessary): If your 2018 Ford F-150 has the PCV valve integrated into the valve cover, you'll need to replace the entire valve cover. This involves removing the old valve cover and installing the new one, following the manufacturer's instructions. Be sure to use a new valve cover gasket to ensure a proper seal.

9. Clear the Code and Retest: After replacing the PCV valve (or valve cover), clear the P0171 code using your OBD-II scanner. Start the engine and let it idle for a few minutes. Monitor the engine for any signs of vacuum leaks or other issues.

10. Drive the Vehicle: Take your 2018 Ford F-150 for a test drive to see if the P0171 code returns. If the code remains clear, the PCV valve was likely the cause of the problem.

As one owner shared: "the valve cover on the 5.0L, so you need the whole cover ($180) or just the PCV ($25 aftermarket). Code cleared and hasn't come back in 2 months. 2018 F-150, 95k miles." (source)

Parts and Tools Needed

Here's a list of the parts and tools you'll need to fix the P0171 code on your 2018 Ford F-150:

• PCV Valve: Aftermarket PCV valves can cost around $25.
• Valve Cover (if necessary): For some 2018 Ford F-150 models with the 5.0L engine, the PCV valve is integrated into the valve cover. A replacement valve cover can cost around $180.
• PCV Hose: If the PCV hose is damaged, you'll need to replace it. The cost of a new PCV hose is typically around $10-$20.
• Valve Cover Gasket (if replacing valve cover): A new valve cover gasket will ensure a proper seal. The cost is around $20-$30.
• OBD-II Scanner: To read and clear the P0171 code.
• Socket Set: For removing and installing the PCV valve or valve cover.
• Screwdrivers: For removing any clips or fasteners.
• Pliers: For disconnecting the PCV hose.
• Torque Wrench (if replacing valve cover): To tighten the valve cover bolts to the manufacturer's specified torque.

Real Owner Costs

The cost to fix a P0171 code on your 2018 Ford F-150 can vary depending on whether you choose to do it yourself (DIY) or take it to a mechanic.

DIY:

• PCV Valve Replacement: If you only need to replace the PCV valve, the cost is relatively low. An aftermarket PCV valve can cost around $25.
• Valve Cover Replacement: If you need to replace the entire valve cover, the cost will be higher. A replacement valve cover can cost around $180.
• Total DIY Cost: $25 - $180 (plus the cost of any tools you may need to purchase).

Professional Repair:

• Diagnosis: Most mechanics will charge a diagnostic fee to determine the cause of the P0171 code. This fee can range from $80 to $150.
• PCV Valve Replacement: The cost to replace the PCV valve at a shop can range from $100 to $300, including parts and labor.
• Valve Cover Replacement: If the valve cover needs to be replaced, the cost can range from $300 to $500, including parts and labor.

As one owner reported, the cost of the PCV valve itself is minimal: "causing a vacuum leak. $25 part, 30 minutes to replace." (source) This highlights the potential savings of doing the repair yourself.

Prevention

Preventing the P0171 code on your 2018 Ford F-150 involves regular maintenance and inspection of your engine's components. Here are some tips to help you avoid this issue:

• Regular PCV Valve Inspection: Inspect the PCV valve and its hose regularly for any signs of damage or wear. Replace the PCV valve every 50,000 to 75,000 miles, or as recommended by your vehicle's maintenance schedule.
• Check for Vacuum Leaks: Periodically check for vacuum leaks around the engine bay, especially near the PCV valve and its connecting hoses. Listen for any hissing sounds that could indicate a leak.
• Maintain Proper Oil Levels: Maintaining proper oil levels is crucial for the health of your engine and its components, including the PCV valve. Low oil levels can cause increased crankcase pressure, which can lead to PCV valve failure.
• Use Quality Fuel: Using high-quality fuel can help prevent deposits from forming in the engine, which can affect the performance of the PCV valve.
• Follow Recommended Maintenance Schedule: Adhere to the recommended maintenance schedule for your 2018 Ford F-150, including oil changes, air filter replacements, and spark plug replacements. This will help ensure that your engine is running smoothly and efficiently.

What Owners Say

Real experiences from FORD owners:

Success Stories

"the valve cover on the 5.0L, so you need the whole cover ($180) or just the PCV ($25 aftermarket). Code cleared and hasn't come back in 2 months. 2018 F-150, 95k miles." — PCVWasTheCulprit ($180) (source)

"Code cleared and hasn't come back in 2 months. 2018 F-150, 95k miles." — PCVWasTheCulprit (source)

Real Repair Costs

"causing a vacuum leak. $25 part, 30 minutes to replace." — PCVWasTheCulprit (source)

"the valve cover on the 5.0L, so you need the whole cover ($180) or just the PCV ($25 aftermarket)." — PCVWasTheCulprit (source)

"After chasing P0171 for months, finally found the culprit - bad PCV valve causing a vacuum leak. $25 part, 30 minutes to replace." — PCVWasTheCulprit (source)

FAQ

Q: How long does it take to fix the P0171 code related to the PCV valve on a 2018 Ford F-150?

A: Replacing the PCV valve is a relatively quick and easy task. Most owners can complete the repair in about 30 minutes to an hour. However, if you need to replace the entire valve cover, the repair may take a few hours, depending on your experience level. As one owner stated, the PCV valve replacement itself took only "30 minutes to replace" (source).

Q: Can I drive my 2018 Ford F-150 with the P0171 code?

A: While it's technically possible to drive with the P0171 code, it's not recommended. The lean condition can cause damage to your engine over time. Additionally, the engine may not run as efficiently, which can lead to decreased fuel economy and performance issues. It's best to address the issue as soon as possible to prevent further damage.

Q: Is the P0171 code a common issue on the 2018 Ford F-150?

A: While not necessarily a widespread problem, the P0171 code can occur on the 2018 Ford F-150, particularly on models with the 5.0L engine. The PCV valve is a common culprit, as it can fail and cause a vacuum leak.

Q: DIY vs mechanic - what's recommended for fixing the P0171 code on a 2018 Ford F-150?

A: If you're comfortable working on your vehicle and have some basic mechanical skills, replacing the PCV valve is a relatively straightforward DIY project. However, if you're not comfortable working on your vehicle or if you're unsure about the diagnosis, it's best to take it to a qualified mechanic. The cost of having a mechanic perform the repair may be higher, but you'll have the peace of mind knowing that the job is done correctly. Additionally, if the PCV valve is integrated into the valve cover and you're not comfortable replacing the entire valve cover, it's best to seek professional assistance.