P0442 Fault Code

Evaporative Emission Control System leak Detected (small leak)

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0442 fault code indicates that the Engine Control Module (ECM) has detected a leak in the Evaporative Emission Control System (EVAP) that is too small to be classified as a larger leak. This system is responsible for preventing fuel vapors from escaping into the atmosphere, and a small leak can result in increased emissions and reduced fuel efficiency.

• Function of EVAP System: The EVAP system captures fuel vapors from the fuel tank and stores them in the charcoal canister until they can be burned in the engine.
• Detection of Leaks: The ECM uses pressure tests to check for leaks in the system and will trigger the P0442 code if a small leak is detected.

What are the symptoms of the P0442 code?

Owners may notice one or more of the following symptoms:

• Check Engine Light (CEL) illuminated.
• No noticeable change in vehicle performance or fuel economy.
• Minor fuel odor in the vehicle’s vicinity.
• Possible diagnostic trouble codes (DTCs) related to the EVAP system being stored along with P0442.

What causes the P0442 code?

Various factors can lead to the P0442 code being set, including:

• Cracked or loose gas cap.
• Faulty fuel filler neck or hoses.
• Damaged or worn EVAP lines.
• Leaking charcoal canister.
• Faulty purge solenoid or vent valve.

How to fix P0442?

To resolve the P0442 fault code, consider the following steps:

• Inspect the gas cap for damage or looseness and replace if necessary.
• Check and replace any damaged EVAP hoses or lines.
• Test the charcoal canister for leaks or cracks, and replace if needed.
• Examine the purge solenoid for proper operation and replace if malfunctioning.
• Perform a smoke test to identify any other sources of leaks in the EVAP system.