← View Generic P0378 Guide Severity: Medium
🚗 Vehicle-Specific Guide

This guide is customized for your 2021 Honda PASSPORT

P0378: P0378: Ignition System Misfire

on 2021 Honda PASSPORT

Fix Cost
$100 - $500
Parts & Labor
Difficulty
3/5
1-2 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 P0378 Mean on 2021 Honda PASSPORT?

A misfire detected in one or more cylinders, affecting combustion efficiency, which can cause decreased engine performance, rough idling, and decreased fuel efficiency.
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Symptoms

  • • Rough idling
  • • decreased engine performance
  • • decreased fuel efficiency
  • • engine misfires
  • • decreased power
  • • and decreased acceleration.
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Common Causes

  • • Faulty spark plugs
  • • ignition coils
  • • fuel injectors
  • • vacuum leaks
  • • faulty crankshaft or camshaft position sensors
  • • and worn or damaged piston rings.
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How to Fix P0378 on 2021 Honda PASSPORT

1. Check and replace spark plugs if necessary. 2. Check and replace ignition coils if necessary. 3. Check and clean or replace fuel injectors if necessary. 4. Check for vacuum leaks and repair if necessary. 5. Check and replace crankshaft or camshaft position sensors if necessary. 6. Check and replace piston rings if necessary.

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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 ↗ fuel injectors Shop ↗ vacuum leak repair kit Shop ↗ crankshaft or camshaft position sensors Shop ↗ piston rings Shop ↗

Essential Tool

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OBD2 Scanner

Read & clear codes on your 2021 Honda PASSPORT

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Related Diagnostic Codes

Other codes that may appear with P0378

P0376 Sequential Code

P0376: Ignition System Misfire

Medium
P0377 Sequential Code

P0377: Ignition System Misfire

Medium
P0379 Sequential Code

P0379: Ignition System Misfire

Medium
P0380 Sequential Code

P0380: Ignition System Misfire

Medium

💡 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