How to Fix P0303 Code on Ford F-150

How to Fix P0303

Experiencing a P0303 code on your 2020 Ford F-150 can be frustrating. This code indicates a misfire in cylinder 3. Luckily, many owners have successfully tackled this issue themselves. As one owner reported: "SOLVED: P0303 Misfire Cylinder 3 - Ignition Coil Fixed it!" (source). This guide will walk you through diagnosing and fixing the P0303 code on your truck, based on the experiences of other 2020 Ford F-150 owners.

Symptoms

The most prominent symptom associated with a P0303 code is a noticeable engine misfire. You might feel this as a jerking or sputtering, especially during acceleration. The severity of the misfire can vary, but it will generally affect your truck's performance and fuel economy.

Another common symptom is a rough idle. When your truck is stationary, such as at a stoplight, the engine might shake or vibrate more than usual. This is due to the inconsistent combustion in cylinder 3. The rough idle can be accompanied by unusual engine noises.

Of course, the presence of the P0303 code itself is a symptom. This code will be triggered by your truck's onboard diagnostic system and can be read using an OBD-II scanner. The check engine light will likely illuminate on your dashboard. It's important to note that while the P0303 code specifically points to cylinder 3, other misfire codes might also be present.

Many owners also report a decrease in overall engine power. This can manifest as difficulty accelerating, reduced towing capacity, or a general sluggishness. The misfire in cylinder 3 disrupts the engine's normal combustion process, leading to a loss of power. This reduction in power can also affect your truck's ability to maintain speed on inclines.

Most Likely Cause

Based on owner reports, the most likely cause of the P0303 code in your 2020 Ford F-150 is a faulty ignition coil on cylinder 3. The ignition coil is responsible for providing the high-voltage spark needed to ignite the air-fuel mixture in the cylinder. When the coil fails, it can cause a misfire, triggering the P0303 code.

The ignition coils can degrade over time due to heat, vibration, and general wear and tear. When one coil fails, it's often a sign that others are also nearing the end of their lifespan. It's important to address this issue promptly to prevent further engine damage.

The misfire occurs because the spark plug in cylinder 3 isn't receiving sufficient voltage to ignite the fuel-air mixture. This results in unburned fuel entering the exhaust system, which can damage the catalytic converter over time. Replacing the faulty ignition coil is typically the most effective solution.

How to Diagnose

Diagnosing a P0303 code on your 2020 Ford F-150 involves a systematic approach to pinpoint the source of the misfire. The first step is to confirm the code using an OBD-II scanner. This will verify that the P0303 code is indeed present and that there aren't any other related codes.

Next, visually inspect the ignition coil on cylinder 3. Look for any signs of physical damage, such as cracks, corrosion, or melted plastic. Also, check the wiring connector to ensure it's securely attached and free from corrosion. If you see any obvious damage, the coil likely needs to be replaced.

If the visual inspection doesn't reveal any issues, you can try swapping the ignition coil on cylinder 3 with a coil from another cylinder. For example, you can swap it with the coil from cylinder 1. After swapping the coils, clear the P0303 code and drive your truck to see if the misfire moves to cylinder 1. If the code changes to P0301 (misfire in cylinder 1), then the original coil is indeed the problem.

If you're still unsure, you can use a multimeter to test the resistance of the ignition coil. Compare the resistance reading of the coil on cylinder 3 with the resistance of a known good coil. A significant difference in resistance can indicate a faulty coil. This test requires some electrical knowledge and familiarity with using a multimeter.

Finally, you can also check the spark plug in cylinder 3. Remove the spark plug and inspect it for signs of wear, fouling, or damage. A worn or fouled spark plug can also cause a misfire. If the spark plug looks questionable, replace it and see if that resolves the issue. Tools required for diagnosis include an OBD-II scanner, basic hand tools (sockets, wrenches), and potentially a multimeter.

Step-by-Step Fix

Here's a step-by-step guide to fixing the P0303 code on your 2020 Ford F-150 by replacing the ignition coil:

1. Gather Your Tools and Parts: You'll need a new ignition coil (or a set of 6, as recommended by some owners), a socket set, a ratchet, an extension, and potentially a torque wrench.

2. Locate Cylinder 3: Cylinder 3 is typically located on one side of the engine, but consult your truck's repair manual or online resources for the exact location.

3. Disconnect the Negative Battery Terminal: This is a crucial safety step to prevent electrical shock or damage to your truck's electrical system.

4. Remove the Engine Cover (if applicable): Some 2020 Ford F-150 models have an engine cover that needs to be removed to access the ignition coils.

5. Disconnect the Wiring Connector: Carefully disconnect the wiring connector from the ignition coil on cylinder 3. There's usually a small clip that needs to be released.

6. Remove the Ignition Coil: Use a socket and ratchet to remove the bolt(s) holding the ignition coil in place. Then, gently pull the coil straight up to remove it.

7. Install the New Ignition Coil: Insert the new ignition coil into the cylinder head, making sure it's seated properly.

8. Reinstall the Bolt(s): Tighten the bolt(s) holding the ignition coil in place. Use a torque wrench to tighten the bolts to the manufacturer's specified torque (if available).

9. Reconnect the Wiring Connector: Reconnect the wiring connector to the ignition coil, ensuring it clicks into place.

10. Reinstall the Engine Cover (if applicable): If you removed an engine cover, reinstall it now.

11. Reconnect the Negative Battery Terminal: Reconnect the negative battery terminal.

12. Clear the P0303 Code: Use an OBD-II scanner to clear the P0303 code from your truck's computer.

13. Test Drive: Start your truck and take it for a test drive to see if the misfire is gone. As one owner shared: "Replaced all 6 coils for $280 (DIY) and the P0303 misfire code is gone." (source).

Important Note: Some owners recommend replacing all ignition coils at once, even if only one is faulty. As one owner stated: "Make sure to replace all coils at once - if one failed, the others are probably close behind." (source). This can help prevent future misfires and ensure consistent engine performance.

Parts and Tools Needed

• New Ignition Coil: Specific part number will vary depending on your 2020 Ford F-150 engine. Search online using your VIN or consult your local auto parts store.
• Socket Set: A standard socket set with various sizes will be needed.
• Ratchet: To turn the sockets.
• Extension: To reach recessed bolts.
• Torque Wrench (Optional): To tighten bolts to the manufacturer's specifications.
• OBD-II Scanner: To read and clear diagnostic codes.

Real Owner Costs

The cost of fixing a P0303 code on your 2020 Ford F-150 can vary depending on whether you choose to DIY the repair or take it to a professional mechanic.

DIY:

• Ignition Coil: A single ignition coil typically costs between $30 and $80.
• Set of 6 Ignition Coils: If you decide to replace all the coils, a set of 6 can cost between $150 and $400.
• Tools: If you already have the necessary tools, there's no additional cost. If you need to purchase tools, a basic socket set can cost between $30 and $100.
• Total DIY Cost: $30 - $400 + Tool Costs

One owner reported: "Replaced all 6 coils for $280 (DIY) and the P0303 misfire code is gone." (source). This provides a real-world example of the cost savings associated with DIY repair.

Professional Mechanic:

• Labor: Labor costs can vary depending on the mechanic's hourly rate and the complexity of the job. Expect to pay between $75 and $150 per hour. Replacing a single ignition coil typically takes 1-2 hours.
• Parts: The mechanic will charge you for the ignition coil, which may be slightly more expensive than buying it yourself.
• Diagnostics: Some mechanics may charge a diagnostic fee to identify the cause of the P0303 code.
• Total Professional Cost: $150 - $500 + (Depending on the shop)

In general, DIY repair is significantly cheaper than taking your 2020 Ford F-150 to a professional mechanic. However, if you're not comfortable working on your truck or don't have the necessary tools, it's best to seek professional help.

Prevention

Preventing a P0303 code on your 2020 Ford F-150 involves regular maintenance and addressing potential issues before they escalate.

One of the most effective preventive measures is to follow the manufacturer's recommended maintenance schedule. This includes replacing spark plugs at the recommended intervals. Worn or fouled spark plugs can put extra stress on the ignition coils, leading to premature failure.

Regularly inspect the ignition coils for any signs of damage, such as cracks, corrosion, or loose wiring connectors. Addressing these issues early can prevent a misfire from occurring.

Consider using high-quality fuel and fuel additives to keep the fuel system clean and prevent deposits from forming on the fuel injectors. Dirty fuel injectors can disrupt the fuel-air mixture, leading to misfires.

If you notice any symptoms of a misfire, such as rough idle or decreased engine power, address the issue promptly. Ignoring these symptoms can lead to more serious engine damage.

Finally, when replacing ignition coils, consider replacing all the coils at once. As one owner mentioned, when one coil fails, the others are likely not far behind. Replacing all the coils can provide peace of mind and prevent future misfires.

What Owners Say

Real experiences from FORD owners:

Success Stories

"SOLVED: P0303 Misfire Cylinder 3 - Ignition Coil Fixed it!" — DIYMechanic (source)

Owner Experiences

"the others are probably close behind. 78k miles on my 2018." — DIYMechanic (source)

Pro Tips from Owners

💡 "Make sure to replace all coils at once - if one failed, the others are probably close behind. 78k miles on my 2018." — DIYMechanic (source)

💡 "Make sure to replace all coils at once - if one failed," — DIYMechanic (source)

Real Repair Costs

"Replaced all 6 coils for $280 (DIY) and the P0303 misfire code is gone." — DIYMechanic (DIY) (source)

"Turns out it was the ignition coil on cylinder 3. Replaced all 6 coils for $280 (DIY) and the P0303 misfire code is gone." — DIYMechanic (DIY) (source)

FAQ

Q: How long does it take to fix a P0303 code on a 2020 Ford F-150?

A: If you're doing it yourself, replacing an ignition coil can take anywhere from 30 minutes to 2 hours, depending on your experience and the location of the coil. A professional mechanic can usually complete the job in 1-2 hours.

Q: Can I drive with a P0303 code?

A: While it's technically possible to drive with a P0303 code, it's not recommended. The misfire can damage your catalytic converter and reduce fuel economy. It's best to address the issue as soon as possible.

Q: Is this a common issue on the 2020 Ford F-150?

A: While not the most common issue, misfires related to ignition coils are a known problem on many vehicles, including the 2020 Ford F-150, especially as the vehicle ages and mileage increases.

Q: DIY vs mechanic - what's recommended?

A: Replacing an ignition coil is a relatively straightforward repair that many owners can do themselves with basic tools and some mechanical knowledge. If you're comfortable working on your truck, DIY is a great way to save money. However, if you're not confident in your abilities, it's best to seek professional help. A mechanic can diagnose the issue accurately and ensure the repair is done correctly.