← View Generic P0309 Guide Severity: High
🚗 Vehicle-Specific Guide

This guide is customized for your 2021 Honda PASSPORT

P0309: Cylinder 9 Misfire Detected

on 2021 Honda PASSPORT

Fix Cost
$20 - $300
Parts & Labor
Difficulty
2/5
30 mins - 2 hours
DIY Possible?
✅ Yes
Save money
Your Vehicle
2021 Honda
PASSPORT
⚠️

Important for 2021 Honda PASSPORT Owners

Before starting repairs, verify which engine your 2021 Honda PASSPORT has. Check your VIN or engine code to ensure you order the correct parts.

📖 What Does P0309 Mean on 2021 Honda PASSPORT?

Engine misfire detected in one or more cylinders affecting combustion efficiency.
⚠️

Symptoms

  • • Rough idle
  • • engine shaking
  • • loss of power
  • • flashing check engine light
  • • poor fuel economy.
🔍

Common Causes

  • • Faulty spark plugs
  • • ignition coils
  • • fuel injectors
  • • compression issues
  • • vacuum leaks.
🛠️

How to Fix P0309 on 2021 Honda PASSPORT

Replace spark plugs and coils, clean fuel injectors, check compression, repair vacuum leaks.

🔧

Need Maintenance Info for Your PASSPORT?

Get oil capacity, filter specs, and torque settings for your specific 2021 Honda PASSPORT.

View 2021 Honda PASSPORT Specs

Parts for 2021 Honda PASSPORT

Spark Plugs Shop ↗ Ignition Coils Shop ↗ Spark Plug Wires Shop ↗

Essential Tool

Must Have

OBD2 Scanner

Read & clear codes on your 2021 Honda PASSPORT

Shop Scanners ↗
🔗

Related Diagnostic Codes

Other codes that may appear with P0309

P0307 Sequential Code

Cylinder 7 Misfire Detected

High
P0308 Sequential Code

Cylinder 8 Misfire Detected

High
P0310 Sequential Code

Cylinder 10 Misfire Detected

High
P0311 Sequential Code

Cylinder 11 Misfire Detected

High

💡 Why These Codes Are Related:

  • • Similar Issues: Same root cause or component failure
  • • Related Problems: Often occur together due to system interactions
  • • Sequential Codes: Progressive failure stages or multiple sensors
  • • Same System: Components within the same automotive system