P0306

High Severity

Cylinder 6 Misfire Detected

Ignition System

P0306 — Instant Answer

Cylinder 6 Misfire Detected

Severity: HIGH SEVERITY

Meaning: Cylinder 6 is misfiring. Only on 6+ cylinder engines.

Safe to drive? NO if CEL is flashing. YES with caution if solid, but repair this week.

Estimated repair cost: $20 - $500

Most common causes:

  • 1. Bad spark plug (35-45% of cases)
  • 2. Faulty coil (35-45% of cases)
  • 3. Bad injector (10-25% of cases)

Symptoms

  • ⚠️Rough idle
  • ⚠️Power loss
  • ⚠️Check engine light

Common Causes

Bad spark pluglikely
Faulty coillikely
Bad injectorpossible

How to Diagnose P0306

  1. 1Swap plug/coil
  2. 2Check injector
  3. 3Compression test

OEM Procedures for P0306

P0306 affects the Spark Plug. Found 116 OEM service manual procedures.

Spark Plug

1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement

Spark Plug
No link

1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement

Spark Plug
No link

1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement

Spark Plug
No link

1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement

Spark Plug
No link

1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement

Spark Plug
No link

1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement

Spark Plug
No link

1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement

Spark Plug
No link

1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement

Spark Plug
No link

Showing 8 of 116 procedures

OEM Diagnostic Flowchart

Scroll to load technician if/then branches.

Read live data and freeze frame for P0306 to pinpoint the cause before buying parts.

Got a repair estimate for P0306? Check if the quote is fair before ordering parts.

Ready to fix it yourself?

Find My Vehicle Repair Guide →

Select your exact vehicle for a personalized step-by-step guide

Priority exact repair pages for this code family

Popular repair guides related to this code.

Related Resources

Repair guides, symptom pages, and wiring diagrams related to P0306.

Frequently Asked Questions

Is cylinder 6 hard to reach?
On V6 engines, cylinder 6 is usually at the back of bank 2. It can be harder to access than front cylinders.
Do I need to replace all 6 coils?
Only if they are all original and high-mileage. Otherwise, just replace the failed one.

Get the Complete Maintenance Schedule for P0306 drivers

Oil, filters, belts, brakes, and fluid intervals sent to your inbox. Unsubscribe anytime.

Not sure you want to DIY? Compare local shop pricing first.

Author & Review

Written by AllOEMManuals Editorial Team. Reviewed by ASE-certified technicians and updated with factory-reference checks for fitment-sensitive steps.

This guide was drafted with AI assistance and reviewed for accuracy by a human editor.

Last updated: 2026-05-07

Need a diagnosis for your specific vehicle?

Start Free AI Diagnosis →

100% Free — No signup required