← View Generic P0178 Guide Severity: Medium

🚗 Vehicle-Specific Guide

This guide is customized for your 2021 Honda PASSPORT

P0178: P0178: Fuel Trim Malfunction (Bank 1)

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

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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 P0178 Mean on 2021 Honda PASSPORT?

The engine control module (ECM) has detected a fuel trim malfunction on bank 1, indicating that the fuel mixture is too lean.

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Symptoms

• Poor engine performance
• rough idle
• decreased power
• and decreased fuel efficiency

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Common Causes

• Faulty oxygen sensor
• clogged fuel filter
• vacuum leaks
• faulty fuel injectors
• or a malfunctioning fuel pressure regulator

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How to Fix P0178 on 2021 Honda PASSPORT

1. Check and clean or replace the fuel filter. 2. Inspect and repair any vacuum leaks. 3. Check and replace the oxygen sensor. 4. Check and clean or replace the fuel injectors. 5. Check and replace the fuel pressure regulator.

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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

fuel filter Shop ↗ oxygen sensor Shop ↗ fuel injectors Shop ↗ fuel pressure regulator Shop ↗

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OBD2 Scanner

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Related Diagnostic Codes

Other codes that may appear with P0178

P0176 Sequential Code

💡 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