P0304 Lincoln 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 Lincoln 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.
Code P0304 Lincoln Description
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.
What are the Possible Causes of the DTC P0304 Lincoln?
- 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 Lincoln?
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
User Submitted Video
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0304 Lincoln 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.
Need more information about the P0304 Lincoln code?
Need more information on how to fix the P0304 Lincoln code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0304 Lincoln code diagnosed by a professional: Find a repair shop in your area
Frequently Asked Questions about P0304 Lincoln Code
1. What does the OBDII code P0304 mean on a Lincoln?
P0304 indicates a misfire has been detected in cylinder 4 of your Lincoln's engine.
2. What are the common symptoms of a P0304 code in a Lincoln?
Symptoms include rough idling, reduced engine performance, poor fuel economy, and possibly the check engine light illuminating.
3. What causes a P0304 code on a Lincoln?
Common causes include a faulty spark plug, ignition coil, fuel injector, vacuum leak, or low cylinder compression in cylinder 4.
4. Can you drive with a P0304 code on a Lincoln?
It’s not recommended to drive for long with this code, as it can cause further engine damage and reduce performance.
5. How do you diagnose the P0304 code on a Lincoln?
Diagnosis typically involves inspecting the spark plug, ignition coil, and fuel injector for cylinder 4, as well as checking for vacuum leaks and performing a compression test.
6. How do you fix the P0304 code on a Lincoln?
Repairs may include replacing the spark plug, ignition coil, or fuel injector for cylinder 4, repairing vacuum leaks, or addressing engine compression issues.
7. Can a bad fuel injector cause a P0304 code on a Lincoln?
Yes, a clogged or malfunctioning fuel injector can prevent proper fuel delivery to cylinder 4, triggering the P0304 code.
8. How much does it cost to fix a P0304 code on a Lincoln?
Costs vary depending on the issue, ranging from $100 to $300 for spark plug or coil replacement to over $1,000 for more complex repairs like addressing compression problems.
9. Can a dirty air filter cause a P0304 code on a Lincoln?
While unlikely, a severely clogged air filter could contribute to engine misfires by affecting air-fuel mixture, but it’s not a primary cause of P0304.
10. What tools are needed to troubleshoot a P0304 code on a Lincoln?
You’ll need an OBDII scanner, a spark plug socket, a multimeter, and possibly a compression tester to diagnose the issue accurately.
Discuss the causes and fixes for P0304 Lincoln OBDII Code
Code P0304 Lincoln comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
