The EVAP system prevents the fumes to disperse in the air. That is to say before fuel vapors are emitted into the atmosphere, the Evaporative Emission System (EVAP) is meant to store and dispose of them. This not only helps the environment but also increases fuel efficiency and removes the stink of gasoline in your cabin.
When the PCM identifies a major leak issue in the EVAP system, the error code P0455 flashes. The primary aim of the EVAP system is to prevent gasoline vapor from exiting the fuel tank and entering the atmosphere. The hoses transport fuel vapors to the charcoal canisters for storage. A purge valve opens as the engine begins, enabling the vacuum to drain off the fuel vapors into the engine.
It is not that critical to resolve the error code P0455. Here are some fixes for dealing with this problem:
OBD2 Code P0455; What is it and what does it indicate?

Error Code P0455: Symptoms, Causes & Fix
OBD2 P0455 Code Error; CausesÂ
The vehicle’s PCM system detects the code that depicts the generic problem. However, the root cause needs to be found. Here are some factors that can cause the PCM to trigger the P0455 OBD2 code error.- A gas cap that is loose or poorly positioned
- The improper gas cap was used (not factory or original brand)
- EVAP system hose leak or damage
- Leak in the fuel tank or the EVAP canister
- A foreign item has been lodged in the gasoline filler cap.
- Fuel tank with a faulty gasket that does not properly seal
- Canister of carbon that has been damaged or divided
OBD2 Error Code P0455; Symptoms
If your vehicle is showing any of these symptoms, there are potential chances of OBD2 Error Code P0455.- The Check Engine Light is illuminated.
- Fuel efficiency has dropped.
- Fuel odor is caused by the discharge of fuel vapor.
OBD2 P0455 Code Error; Diagnosis
The right diagnosis of the main issue can save you from unnecessary fixes or replacements. Thus, saving your time and money. Here are some steps you can perform on your own to diagnose po455 code errors.Â- To ensure a sealed fuel tank, remove the gas cap and reattach it snugly.
- Clear the OBD2 error codes from the scanning tool
- Drive your vehicle for a day to see whether the code reappears.Â
- If the issue still prevails, you should inspect the old gas cap and replace it with a new one if it doesn’t feel snug and secure.
- Examine the EVAP system for damage, such as cuts or holes in the tubes and hoses.Â
- Also, make sure the EVAP canister purge volume control solenoid valve is working properly. You can locate the purge volume control solenoid by following the vacuum line from your intake manifold. ​
- After that, disconnect the 2-pin waterproof connection and check for power and signal. It’s as simple as disconnecting the connection and inspecting the hoses for leaks.Â
- To discover leaks, fill a container with soapy water and gently spray it on the hoses.
- Then follow the vacuum line down to the EVAP resonator. It’s the green-capped plastic 1-way valve that connects to the EVAP service port.Â
- Remove the adapter for the EVAP service port and perform a pressure test before checking for leaks.Â
- Replace the vacuum line after you’ve located the leak.Â
Mistakes to Avoid When Diagnosing The P0455 Code
The wrong diagnosis can lead you to cost more than expected and still keep the issue reappearing. You do not want that? Here are mistakes you should avoid while diagnosing the code error.Â- Do not skip or hasten the diagnostic process.Â
- Make sure to follow all the steps in the right order.Â
Fix P0455 Obd2 Code: Evaporative Emission Control System Gross LeakÂ

- Gas cap replacement
- The gasoline filler neck was replaced.
- Any hose issues should be repaired or replaced.
Vehicles that usually face P0455 issues?
- P0455 AcuraÂ
- P0455 HondaÂ
- P0455 MitsubishiÂ
- P0455 AudiÂ
- P0455 HyundaiÂ
- P0455 NissanÂ
- P0455 BMWÂ
- P0455 InfinitiÂ
- P0455 PorscheÂ
- P0455 BuickÂ
- P0455 JaguarÂ
- P0455 SaabÂ
- P0455 CadillacÂ
- P0455 JeepÂ