Engine-CodesGMC – P0442 2017 GMC Sierra

P0442 2017 GMC Sierra Code - Evaporative Emission System Small Leak Detected

Quick Answer

The P0442 code indicates that the evaporative emission control system has detected a small leak. Common causes include Loose or damaged gas cap, Cracked or disconnected hoses, Faulty purge valve. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means
P0442 2017 GMC Sierra indicates Evaporative Emission System Small Leak Detected.
Common causes
Common causes include Loose or damaged gas cap, Cracked or disconnected hoses, Faulty purge valve.
Severity
Low - monitor the vehicle and repair when practical.
Can I drive?
The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
Table of contents Created and updated by William Orellana on Sep 09, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0442 2017 GMC Sierra Description

The P0442 code indicates that the evaporative emission control system has detected a small leak. This system is designed to prevent fuel vapors from escaping into the atmosphere and is crucial for reducing vehicle emissions. When a small leak is detected, it means that the system is not able to maintain the required pressure, leading to potential emissions of harmful gases.

OBDII Code P0442 2017 GMC Sierra - Evaporative Emission System Small Leak Detected
P0442 2017 GMC Sierra Code - Evaporative Emission System Small Leak Detected

Common Causes of P0442 2017 GMC Sierra

  1. Loose or damaged gas cap
  2. Cracked or disconnected hoses
  3. Faulty purge valve
  4. Cracked charcoal canister
  5. Leaking fuel tank

Symptoms of P0442 2017 GMC Sierra

  1. Check engine light illuminated
  2. Fuel odor inside or outside the vehicle
  3. Decreased fuel efficiency
  4. Failed emissions test

How to Fix P0442 2017 GMC Sierra

  1. Check the gas cap and ensure it is properly tightened or replace it if damaged.
  2. Inspect and replace any cracked or disconnected hoses in the evaporative emission system.
  3. Test the purge valve to ensure it is functioning properly and replace it if necessary.
  4. Inspect the charcoal canister for cracks and replace it if damaged.
  5. Check the fuel tank for leaks and repair or replace it if necessary.

Cost to Fix P0442 2017 GMC Sierra

The cost of repairing a P0442 code can vary depending on the specific cause of the issue and the labor rates at the repair shop. Generally, repairing a small leak in the evaporative emission system can cost anywhere from $100 to $500, including parts and labor. It's important to consider that diagnostic time and labor rates can vary, so it's recommended to get a specific estimate from a qualified mechanic.

Tech Notes for P0442 2017 GMC Sierra

The P0442 code means that the control module has detected a small leak in the Evaporative Emission (EVAP). A loose fuel tank filler cap is the most common cause that will trigger the P0442 code.



There is a factory service bulletin for all the models from 2000 through 2021. The factory states that there are seven critical connections that could likely lead to this DTC being set:

1. Purge tube to purge valve (at intake manifold)

2. Purge tube to chassis EVAP line (at the rear of the engine, near transmission)

3. Chassis EVAP line to canister (at canister)

4. Fuel tank load line to canister (at canister)

5. Vent valve line to vent valve (at vent valve)

6. Fuel tank load line jumper connection (near fuel tank)

7. Fuel tank cap is closed properly (at refuel compartment)

Need more information about the P0442 2017 GMC Sierra code?

Need more information on how to fix the P0442 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0442 2017 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0442 2017 GMC Sierra Code

No Frequently Asked Questions about P0442 2017 GMC Sierra Code found.

Discuss the causes and fixes for P0442 2017 GMC Sierra OBDII Code

Code P0442 2017 GMC Sierra comments

No comments found for this page.