P0455 OBD-II Trouble Code: System Gross Leak Evaporative Emission

Our certified mechanics come to you · 12-month, 12,000-mile warranty

SCHEDULE P0455 DIAGNOSTIC Get a fair and transparent estimate upfront
Red-stars EXCELLENT RATING ON

Cost of diagnosing the P0455 code

P0455 is a diagnostic trouble code (DTC) for "System Gross Leak Evaporative Emission". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $79.99. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.

Cars Estimate Credit towards follow-up repair Earliest Availability
Ford$79.99$20.00
Toyota$79.99$20.00
BMW$79.99$20.00
SCHEDULE P0455 DIAGNOSTIC Get a fair and transparent estimate upfront

check engine light logo

P0455 Trouble Code definition

System Gross Leak Evaporative Emission

The Code P00455 code is often associated with P0440 code.

What the P0455 code means

P0440 is the general code for a problem with the Fuel Evaporative Emission System. The P0455 code specifically indicates a large leak in the system, not a fuel leak, but one in the vapor recovery system.

What causes the P0455 code?

The leak can be caused from a variety of components. The most common is related to the fuel filler cap which could be missing, not correctly installed, not sealing properly or may be damaged to the top of the filler neck.

The next most frequent problem is a leak in a hose. Hoses on the breather system tend to crack with age including the large connecting hose on the filler neck to the tank. The Evaporative Emission System has a purge valve to regulate pressure in the system and this will need to be checked by a technician.

Vehicles with a charcoal filter on their evaporative system need to check the filter for cracks, damage, or leaks. The fuel tank itself may be leaking or the gasket where the fuel level sensor, pressure sensor, and fuel pick attach to the tank may be leaking. See the manufacturer's diagram of the system to verify components and their locations. Note that even if the code indicates a large leak, it may actually be fairly small.

What are the symptoms of the P0455 code?

P0455 will generally be preceded by the Check Engine Light coming on the dashboard’s display. There can be a noticeable gasoline fuel smell in the filler area or tank area. It is also possible the smell could also becoming from the evaporative lines to the engine intake system.

How does a mechanic diagnose the P0455 code?

P0455 is diagnosed with an OBD-II scanner. The technician should then reset the OBD-II fault codes and road test the vehicle to see if the code comes back and he can observe this by watching it live on his scanner while driving.

If the code comes back, then the mechanic will need to do a visual inspection to determine any obvious leaks. If no leaks are seen, then the next step is to use a smoke test on the system to look for a leak. If there is no leak noted, then there may be a sensor issue that will need to be tested by the manufacturer's instructions as each system is slightly different.

Common mistakes when diagnosing the P0455 code.

Diagnostic errors are largely due to not following the procedure. The process is a logical and economically sound way to proceed. If you need a fuel cap, they are usually less than $30, but other components such as the Evaporative Emission System purge valve can cost several hundred dollars

How serious is the P0455 code?

P0455 code will not affect the way the car drives, but if the fuel odors are very strong or have obvious fuel leaks, take the car to a qualified technician as soon as possible. The system leak failure can cause excessive fuel consumption in certain circumstances so it is best to take to a technician at your first opportunity. Occasionally, if no problems are found, the technician can reset the fault codes, then retest. Note, that to do proper testing the fuel tank, it should be 1/4 to 3/4 full to ensure proper conditions to test. Often times, if the Check Engine Light came on immediately at start up, the OBD-II system can be reset and the vehicle will operate normally.

Often times, if the Check Engine Light came on immediately at start up, the OBD-II system can be reset and the vehicle will operate normally.

What repairs can fix the P0455 code?

Potential repairs to P0455 are:

Additional comments for consideration regarding the P0455 code.

Many vehicles with mileage over 100,000 have momentary sensor problems that usually occur during start up or prolonged stress situations on the drive train. If the Check Engine Light comes on and the vehicle seems to be operating normally, the OBD-II system can be reset using the scanner and the problem may not reoccur. This is why it is important to verify the fault and reset it before doing any repairs.

Need help with a P0455 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

Check Engine Light
trouble codes
P0455

Fast and easy Check Engine Light is on Inspection service at your home or office.

SCHEDULE P0455 DIAGNOSTIC
Get a fair and transparent estimate upfront

Recent Check Engine Light is on Inspection reviews

Excellent Rating


YourMechanic Check Engine Light is on Inspection Service

Average Rating

4.8/5

Number of Reviews

4,255

Rating Summary
3,898
174
45
26
112
3,898
174
45
26
112
Ben

Ben

39 years of experience
1020 reviews
Ben
39 years of experience
Lexus LS430 - Check Engine Light is on - Houston, Texas
I was very pleased with the courtesy and work of Mr. Smith. He was exceptional in explaining and correcting the problem and thereby gained my trustI . I request he be my mechanic in all future service requests. I had a great experience working with Mr. Ben Smith.
Richard

Richard

19 years of experience
203 reviews
Richard
19 years of experience
Ram ProMaster 1500 - Check Engine Light is on - Bonita Springs, Florida
Prompt, polite and personal. Took the time to explain the process and his recommendations. 2 thumbs up
Michael

Michael

23 years of experience
37 reviews
Michael
23 years of experience
Ford F-150 - Check Engine Light is on - Federal Way, Washington
Very helpful and explained everything and what needs to be addressed. I feel informed and confident in Mike’s assessment and look forward to him performing services on my vehicle.
Rigoberto

Rigoberto

9 years of experience
650 reviews
Rigoberto
9 years of experience
Honda Civic - Check Engine Light is on - Chicago, Illinois
Rigoberto came on time & quickly diagnosed the problem- rats chewed thru wiring near the battery. He wasn’t able to fix it himself bc of parts, but gave me recommendations on where to go & how to not have the dealership sell me services that are not needed.

More related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...

Related questions

Q: My car has trouble code P0745, do I need to replace the solenoid?

Diagnostic Trouble Code P0745 refers to out of range voltage at a solenoid-operated valve that regulates hydraulic pressure in the transmission based on outputs from the Transmission Control Module (TCM). Code P0745 is set when the TCM sees an out...

Q: All engine sensor failure, transmission problems after a car wash.

Hi there. The only thing that could cause the severe issues that you are having with your vehicle is a leak in the exhaust system and having cold water enter the catalytic converter causing the chamber to collapse. Check the...

Q: Battery malfunctioning

P0341 is a camshaft position sensor error code while P0455 indicates a large evaporative emissions leak, such as a failed gas tank cap seal. These are likely not related to the battery malfunction. Have a mechanic, like the ones at...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1-800-701-6230 · hi@yourmechanic.com