EVAP code p0442 chevy

Chevy Error Codes Forum
1

My 2010 Chevy Cobalt threw a check engine light with a code for a small EVAP leak. I replaced the gas cap today, hoping the light resets.

Any ideas what else it could be if the light stays on?

Thanks for any help!

2

After replacing the gas cap, if the check engine light is still on, there may be a tiny EVAP leak that is the result of a malfunctioning vent valve, purge valve, or leak in the EVAP canister or hoses. The precise location of the leak may be found with the use of a smoke test. Speaking with a mechanic is recommended.

3

If changing the gas cap on your 2010 Chevy Cobalt doesn’t stop the check engine light from coming on for a minor EVAP leak, you might want to look for leaks or damage in the EVAP system’s purge valve, vent valve, and EVAP canister. It could also be helpful to look for any cracks or loose fittings in the hoses and connectors.

4

Diagnostic trouble code (DTC) P0442 stands for “Evaporative Emission Control System Leak Detected (Small Leak)”. Your car’s computer will set the code when it determines there’s a minor leak somewhere in the evaporative emission control (EVAP) system.

5

So, a P0442 code means there’s a leak in the system that controls gas fumes, but it’s a minor one? Is that right?

6

Replacing the gas cap is a common fix for a small EVAP (Evaporative Emission Control System) leak code. However, if the check engine light remains on after replacing the cap, there could be other causes for the EVAP leak in your 2010 Chevy Cobalt. Here’s what you can do next:

Double-Check the Gas Cap:

  • Ensure Proper Tightness: Make sure the gas cap is tightened securely. A loose gas cap can cause a leak and trigger the check engine light.
  • Check the New Cap: If you’ve installed a new gas cap, there’s a chance it might be faulty. Try using your old gas cap (if it’s still in good condition) to see if the light goes off.

Next Steps if the Light Persists:

  1. Smoke Test:
  • This diagnostic test involves introducing smoke into the EVAP system to identify the leak visually. A mechanic can perform a smoke test to pinpoint the exact location of the leak.
  1. Common Leak Locations:
  • EVAP Canister Vent Solenoid: This solenoid regulates airflow in the system, and a malfunction can cause a leak.
  • Vacuum Lines: Cracked or loose vacuum lines are common sources of leaks.
  • Purge Control Valve: This valve controls the flow of fuel vapors, and a malfunction can lead to a leak.

Diagnosis and Repair:

  • Identify the Leak Source: Once the leak source is identified, a mechanic can recommend the appropriate repair.
  • Replace Faulty Components: This might involve replacing the faulty component (e.g., gas cap, solenoid, purge valve) or repairing cracked vacuum lines.