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 $70.00. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $30.00 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$70.00$30.00
Toyota$70.00$30.00
BMW$70.00$30.00
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

4.5/5

Number of Reviews

3,484

Rating Summary
3,176
153
40
23
92
3,176
153
40
23
92

Richard

10 years of experience
415 reviews
Richard
10 years of experience
This is the second time I’ve had Richard work on my car. He always does an outstanding job and is quick, knowledgeable and professional. Highly recommended!!
2012 DODGE CHALLENGER - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Michael

13 years of experience
372 reviews
Michael
13 years of experience
Mike was an absolute professional when he arrived. He walked me thru the whole process of my repairs and also made good recommendations for preventive issues. His mechanical knowledge and good customer services was a breath of air and greatly appreciated :-)
2007 CHEVROLET AVALANCHE - CHECK ENGINE LIGHT IS ON INSPECTION - MARIETTA, GEORGIA

Rodrigo

10 years of experience
85 reviews
Rodrigo
10 years of experience
Rodrigo was exactly on time, very professional and friendly. He assessed my car, let me know the exact problem when a previous mechanic from a shop in my area was unable to. I felt he was very honest and sincere letting me know the level of urgency that I deal with the issue. Absolutely no pressure. I will absolutely use Rodrigo the next time I need anything to do with my car and will tell everyone about him. This is such a great service, I will never go to another mechanic again. It is so convenient. I couldn’t be happier. :)
2013 SMART FORTWO - CHECK ENGINE LIGHT IS ON - LAS VEGAS, NEVADA

Ricardo

8 years of experience
223 reviews
Ricardo
8 years of experience
Great service and was very helpful on what maintenance my vehicle needed and what to expect in the future. Would definitely recommend to anyone and will.
2004 MITSUBISHI LANCER - CHECK ENGINE LIGHT IS ON - LOS ANGELES, CALIFORNIA

More related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...
Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...

Related questions

Q: I have a 2012 cc with a p0016 code no start. chain is tight and all turns freely when turned by hand

Code P0016 broadly means that the PCM has detected that the Crankshaft and Camshaft are out of sync. If they are out of sync beyond a specific, threshold number of degrees, the car simply won't start. The cause of that...

Q: My vehicle runs or idles rough. I was told that is normal, is it? And what are the signs of the transmission going out?

With a vehicle as new as yours, the likelihood of a transmission issue would be fairly slim unless damage has been done. The clanking and the rough idle may be the cause of the jerking motion. You should turn your...

Q: Check Engine Light is on - code P0455

Hello. P0455 is the trouble code for a large leak detected by the evaporative emissions control system. The computer will set off this code if it detects a large leak in the evaporative emissions (EVAP) system. The EVAP emissions system...

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