How can I fix the error code P0455?

Alton Alexander
By Alton AlexanderUpdated on June 4th, 2022

The PO455 error code indicates that there is a problem with the evaporative emissions system. This system is responsible for collecting and storing fuel vapors from the engine so that they can be burned off later. If there is a leak in this system, it can cause the engine to run lean and produce too much emissions.

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  • evap error code
  • po455

1. The most common cause of P0455 is a faulty gas cap

  1. Place the car in park and secure the parking brake.
  2. Remove the cap and secure it with a rag or piece of cloth.
  3. Inspect the seal around the gas cap for any signs of leakage.
  4. If there are no signs of leakage, replace the gas cap.
  5. If there are signs of leakage, replace the gas cap and the gas pump.

2. A torn or leaking EVAP hose can also cause P0455

1.Remove the air cleaner assembly. 2.Remove the fuel tank. 3.Remove the EVAP hose. 4.Clean the area around the hose with a solvent. 5.Replace the hose. 6.Install the fuel tank, air cleaner assembly, and EVAP hose.

3. A loose, damaged or missing gas cap can also cause P0455

One way to fix P0455 is to replace the gas cap. To do this, you'll need to remove the gas cap, and then replace the gas cap seal. If the gas cap is loose, damaged, or missing, you'll also need to replace the gas cap gasket.

4. The EVAP canister may be damaged or missing

  1. Check all connectors and hoses to make sure they are connected properly.
  2. Check the Evaporative Emission Control System (EVAP) canister for damage or missing components.
  3. Replace the damaged or missing EVAP canister.

5. The EVAP purge valve may be stuck open

  1. Remove the rear seat to gain access to the EVAP purge valve.
  2. Check the valve for proper operation by removing the cap and pressurizing the system. If the valve opens and the purge gas escapes, the valve is probably stuck open.
  3. If the valve is stuck open, remove the valve assembly by carefully prying it off the pipe. Clean the area around the valve of any debris that may have collected.
  4. Reinstall the valve assembly and cap, making sure they are properly seated. Pressure the system and check for proper operation.

If you didn't find success with an option above, then try:

  1. The EVAP vent valve may be stuck open. Inspect the valve and replace if necessary.
  2. The EVAP system may have a leak. Inspect the system and repair or replace as necessary.