AutoCodesFord – P0304 2001 Ford F150

P0304 2001 Ford F150 Code - Cylinder 4 Misfire Detected

Quick Answer

Misfire is defined as a lack of combustion in a cylinder due to the absence of a spark, incorrect fuel metering, low compression, or any other cause. Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0304 2001 Ford F150 indicates Cylinder 4 Misfire Detected.
Common causes
Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code Popularity 7,732
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Apr 09, 2023
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Code P0304 2001 Ford F150 Description

Misfire is defined as a lack of combustion in a cylinder due to the absence of a spark, incorrect fuel metering, low compression, or any other cause.
When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.
The Malfunction Indicator Lamp (MIL) blinks once per second when detecting a misfire severe enough to cause catalyst damage. If the MIL is in a steady state due to a misfire, this indicates the threshold for emissions was exceeded and caused the vehicle to fail an inspection and maintenance tailpipe test.
This Diagnostic Trouble Code (DTC) sets when the misfire detection monitor detects an engine misfire in cylinder 4.
OBDII Code P0304 2001 Ford F150 - Cylinder 4 Misfire Detected - AutoCodes.com
P0304 2001 Ford F150 Code - Cylinder 4 Misfire Detected

What are the Possible Causes of the DTC P0304 2001 Ford F150?

  • Faulty Spark Plug #4
  • Clogged or faulty Fuel Injector #4
  • Faulty Ignition Coil #4
  • Fuel Injector #4 harness is open or shorted
  • Fuel Injector #4 circuit poor electrical connection
  • Ignition Coil #4 harness is open or shorted
  • Ignition Coil #4 circuit poor electrical connection
  • Insufficient cylinder 4 compression
  • Incorrect fuel pressure
  • Intake air leak

How to Fix the DTC P0304 2001 Ford F150?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

Code Tech Notes

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0304 2001 Ford F150 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0304 2001 Ford F150 Code

1. What does the OBDII code P0304 mean on a 2001 Ford F150?

P0304 indicates that the engine’s onboard computer has detected a misfire in cylinder 4.

2. What are the symptoms of a P0304 code on a 2001 Ford F150?

Symptoms may include rough idling, reduced engine performance, poor fuel economy, and possibly the check engine light illuminating.

3. What causes a misfire in cylinder 4 on a 2001 Ford F150?

Common causes include a faulty spark plug, a bad ignition coil, a clogged fuel injector, low cylinder compression, or vacuum leaks near cylinder 4.

4. Can a bad spark plug cause the P0304 code?

Yes, a worn or damaged spark plug in cylinder 4 is a frequent cause of this code and should be checked first.

5. How do I diagnose the P0304 code on my 2001 Ford F150?

Start by inspecting the spark plug, ignition coil, and fuel injector for cylinder 4. Check for vacuum leaks, wiring issues, and perform a compression test if necessary.

6. Can driving with a P0304 code damage my engine?

Yes, driving with a cylinder misfire can cause damage to the catalytic converter or engine components over time. It’s best to address the issue promptly.

7. How can I fix the P0304 code on my 2001 Ford F150?

Repairs may include replacing the spark plug or ignition coil for cylinder 4, cleaning or replacing the fuel injector, fixing vacuum leaks, or addressing low compression issues.

8. Is the ignition coil a common problem for P0304 on a 2001 Ford F150?

Yes, ignition coil failure is a common issue for this model and can often trigger a cylinder misfire code like P0304.

9. How much does it cost to repair the P0304 code on a 2001 Ford F150?

Costs vary depending on the issue, but replacing a spark plug or ignition coil can cost $50-$300, while more extensive repairs like addressing low compression may cost significantly more.

10. Can a clogged fuel injector cause the P0304 code?

Yes, a clogged or malfunctioning fuel injector can prevent proper fuel delivery to cylinder 4, resulting in a misfire.

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