P0455 on Toyota: How to Diagnose & Fix
Evaporative Emission Control System Leak Detected (Gross Leak)
6 Toyota models · 7 documented issues · $20-$2,500 repair
P0455 on Toyota by model: symptoms, diagnosis and fix
The FJ Cruiser's A/C system is prone to compressor clutch failure and evaporator core leaks. The evaporator is located behind the dashboard, making replacement extremely labor-intensive. The A/C system struggles in hot climates, especially when off-roading at low speeds.
Common Symptoms
- A/C blows warm air
- A/C compressor clicking on and off rapidly
- Weak airflow from vents
- Musty smell from vents (evaporator leak)
- Refrigerant needs recharging frequently
How to Fix
For compressor clutch: replace A/C compressor assembly (Denso 471-1026 or Toyota 88310-35C60). For evaporator: replace evaporator core (Toyota 88501-35120) - this is a full dash removal job, 8-12 hours labor. Replace receiver/drier, expansion valve, and O-rings whenever the system is opened. Evacuate and recharge with R-134a.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota 88320-35700 genuine cooler compressor assembly
early compressor branch after pressure, electrical and mechanical diagnosis confirms compressor failure Fitment/availability: Cataloged for 2007-2010 Toyota FJ Cruiser 4.0L; production overlap requires VIN confirmation Fitment/availabili…
- Toyota 88320-6A540 genuine compressor assembly
late compressor branch after pressure, electrical and mechanical diagnosis confirms compressor failure Fitment/availability: Cataloged for 2010-2014 Toyota FJ Cruiser 4.0L; production overlap requires VIN confirmation Fitment/availabilit…
- Toyota 88501-35151 genuine A/C evaporator core
evaporator replacement only after an electronic/dye leak test localizes refrigerant loss to the evaporator Fitment/availability: 2007-2014 Toyota FJ Cruiser; replaces 88501-35150, 88501-60300 and 88501-60430; confirm VIN/current superses…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
The A/C system can develop a musty or moldy smell when first turned on. This is caused by moisture accumulation and mold/bacteria growth on the evaporator. Common in humid climates and vehicles that use A/C infrequently.
Common Symptoms
- Musty smell when A/C starts
- Mold or mildew odor
- Smell goes away after a few minutes
- Worse in humid weather
- Allergic reactions possible
How to Fix
Use A/C evaporator cleaner spray through the cabin air filter opening or vents. Replace cabin air filter regularly. Run A/C on fresh air mode for a few minutes before turning off to dry evaporator. Professional evaporator cleaning available.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota 00289-ACRKT genuine A/C Refresher Kit
clean and deodorize a contaminated evaporator case Fitment/availability: Toyota evaporator deodorizing/cleaning service kit; use only after confirming the odor is microbial evaporator contamination and follow the kit procedure Fitment/av…
- Toyota 88508-04010 genuine deodorant cabin-air filter
replace a dirty or odor-contaminated cabin filter after the odor source is corrected Fitment/availability: 2016-2023 Toyota Tacoma cabin-filter application; confirm VIN and HVAC housing Fitment/availability: Add to Cart live when reviewed
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipReplace cabin air filter regularly.
- TipGet a proper diagnosis before replacing parts - similar symptoms can have different causes
Sources for this issue (1)
Tacomas in this era commonly develop EVAP system leak faults that trigger a check engine light, often caused by a failing charcoal canister, stuck vent valve, cracked hoses, or a rusted filler neck in salt-belt trucks. Owners usually notice no drivability problem, but the truck will not pass emissions and the light often returns after a gas cap replacement. The pattern is well documented in NHTSA complaints, forum troubleshooting threads, and repair databases.
Common Symptoms
- check engine light on
- emissions test failure
- no noticeable drivability issue
- fuel smell near rear of truck in some cases
- code returns after replacing gas cap
How to Fix
Proper diagnosis requires smoke-testing the EVAP system rather than guessing, with close inspection of the gas cap seal, canister, vent valve, purge valve operation, hoses, and filler neck. Depending on the leak source, repairs range from replacing the cap or vent valve to replacing the charcoal canister assembly or corroded filler neck. Clearing codes without smoke-testing often leads to repeat repairs.
Sources for this issue (1)
Toyota T-SB-0046-10 applies to specified 2006-2010 RAV4 production and addresses liquid fuel entering the EVAP system. The documented gates are an illuminated MIL with DTC P043E, P043F, P2401, P2402 and/or P2419, or an intermittent warm rough idle reproduced while commanding the purge VSV, followed by physical confirmation of fuel in the applicable EVAP vent hoses. It is not a general 2001-2012 charcoal-canister failure card and does not support the old P0440/P0441/P0442/P0446/P0455 mapping.
Common Symptoms
- MIL with one or more supported EVAP DTCs
- Intermittent rough idle at operating temperature during the bulletin's purge-VSV test
- Liquid fuel physically confirmed in a specified EVAP vent hose
How to Fix
Follow T-SB-0046-10's sequence: check for the supported DTCs; if none are stored, active-test the purge VSV at warm idle; then disconnect and inspect the specified tank-to-canister and canister-to-key-off-pump hoses for liquid fuel. If the gates are not met, the bulletin does not apply and normal EVAP diagnosis continues. If fuel is confirmed, the required tank, canister and possibly canister-filter/protector scope depends on which hose contains fuel. Do not replace a gas cap, vent valve or full canister from a generic code list. The former federal and California emissions-warranty windows are expired; obtain a diagnosis and estimate first.
Owner tips & cautions
- TipSave freeze-frame data and all EVAP codes before clearing them; the bulletin requires exact code/test and liquid-fuel confirmation gates.
- WarningDo not guess at an EVAP canister, gas cap or vent valve from a generic code; T-SB-0046-10's component scope changes based on where liquid fuel is found.
Sources for this issue (1)
Third-generation Siennas commonly throw EVAP (evaporative emissions) faults as the system ages. Failure points include the canister vent solenoid/VSV sticking, the leak-detection pump and reference orifice, the purge valve, and a worn or loose gas cap. Beyond the check engine light and an emissions/smog failure, a stuck-closed vent can make the tank hard to refuel (pump clicks off repeatedly), while a stuck-open vent or cracked line can produce a fuel-vapor smell.
Common Symptoms
- Check engine light with EVAP codes
- Fails state emissions/smog test
- Gas pump clicks off repeatedly / difficult to refuel
- Faint fuel-vapor smell near the vehicle
- No drivability change but persistent CEL
How to Fix
Check the gas cap first, then smoke-test the EVAP system to find leaks. Codes guide the fix: P043E/P043F point to a clogged or ruptured reference orifice, P2401/P2402/P2419 to the leak-detection pump/switching valve, and P0441/P0446/P0455 to purge/vent flow or large leaks. Typical repairs (vent solenoid, purge VSV, leak-detection pump, or hoses) run roughly $150-$500 including diagnosis.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota 77300-06040 fuel tank cap assembly
replace a cap that fails seal, tether or ratchet inspection on the matching early branch Fitment/availability: Early fuel-cap branch cataloged for Sienna through the relevant early third-generation production; confirm VIN and production …
- Toyota 77300-07030 fuel tank cap assembly
replace a cap that fails inspection on the matching middle production branch Fitment/availability: Middle fuel-cap branch cataloged for 2013-2017 Sienna with production-date overlap; confirm VIN against the catalog before ordering Fitmen…
- Toyota 77300-07040 fuel tank cap assembly
replace a cap that fails inspection on the matching late production branch Fitment/availability: Late fuel-cap branch used from the applicable 2016/2017 production change through 2020; confirm VIN and build date Fitment/availability: Shi…
- Toyota 77740-08070 charcoal canister assembly
replace the early canister only after smoke/active testing confirms its internal pump, orifice, vent or canister failure Fitment/availability: Canister branch cataloged for 2011-2016 Sienna and some 2017 applications; confirm VIN, drivet…
- Toyota 77740-08090 charcoal canister assembly
replace the late canister only after smoke/active testing confirms its internal pump, orifice, vent or canister failure Fitment/availability: Canister branch cataloged for 2017-2020 Sienna 3.5L; confirm VIN and production because 2017 ov…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (3)
The evaporative-emissions system commonly sets P0441 (incorrect purge flow) and P0455/P0446 (large leak / vent malfunction). The vapor canister purge valve (VSV) sticks open or closed, or the charcoal canister breaks down internally and sheds pellets that clog the system. A classic symptom is the gas-pump nozzle repeatedly clicking off before the tank is full, plus a fuel-vapor smell. A loose/failed gas cap or cracked filler-neck boot can also set the codes.
Common Symptoms
- Check engine light P0441 / P0455 / P0446
- Gas pump clicks off repeatedly while fueling
- Fuel/vapor odor
- Slight rough idle after refueling
- Failed emissions/EVAP test
How to Fix
Start with the cheapest causes: reseat/replace the fuel cap and inspect the filler-neck boot. Test the purge VSV and vent valve; replace the sticking solenoid (e.g., Genuine purge valve 25860-0P090 on 2008–2011 3.5L applications — verify by VIN as part numbers were superseded). If charcoal is contaminating the lines, replace the vapor canister and clear the pellets from the purge/vent circuit.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota 90910-12204 genuine duty vacuum switching valve
replacement purge/VSV only after testing proves this engine-specific valve sticks, leaks or fails to actuate Fitment/availability: VIN-confirmed 2008-2013 Highlander gas 3.5L 2GR-FE purge/VSV branch whose Toyota diagram calls for 90910-1…
- Toyota 90910-12276 genuine duty vacuum switching valve
replacement purge/VSV after electrical, sealing and flow testing identifies this exact valve Fitment/availability: VIN-confirmed Highlander gas branch whose current vacuum-piping diagram calls for 90910-12276 or 90910-TC001; the reviewed…
- Toyota 77740-0E020 genuine charcoal canister assembly
replacement canister only after smoke/flow testing or visible charcoal contamination proves the canister is leaking, restricted or breaking down Fitment/availability: VIN-confirmed 2008-2013 Highlander gas ASU40/GSU40/GSU45 branch; repla…
- Toyota 77300-06040 genuine fuel-tank cap assembly
lowest-cost replacement only when inspection or cap testing confirms a damaged seal, ratchet or sealing surface Fitment/availability: VIN-confirmed 2008-2013 Highlander branch using 77300-06040; verify emissions package and current super…
- Toyota 77300-07030 genuine fuel-tank cap assembly
replacement cap only when the later-generation cap or seal is proven unable to hold the EVAP test pressure Fitment/availability: VIN-confirmed 2014-2017 Highlander gas ASU50/GSU50/GSU55 branch; Hybrid and later vehicles have separate cat…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (2)
P0455 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0455 mean on a Toyota?
P0455 stands for "Evaporative Emission Control System Leak Detected (Gross Leak)." This code means your car's evaporative emission (EVAP) system has detected a large (gross) leak, so fuel vapors that should be sealed inside the fuel and vapor system are escaping into the atmosphere. The EVAP system captures gasoline vapors from the tank and routes them to the engine to be burned instead of polluting the air, and the computer periodically pressure- or vacuum-tests this sealed system. A gross leak almost always points to something obvious and easy, like a loose, missing, or bad gas cap, rather than a deep mechanical failure. It rarely affects how the car drives, but it should be fixed to pass emissions and stop wasting fuel vapor. On Toyota it is documented across 6 models: FJ Cruiser, Tacoma, RAV4, Sienna, Highlander, Corolla.
What are the most common causes of P0455?
The most common causes of P0455 are: Loose, missing, or improperly tightened gas cap, Worn, cracked, or failed gas cap seal, Cracked or disconnected EVAP/vapor hose, Damaged or missing fuel filler neck seal, Faulty EVAP purge valve stuck open, Failed EVAP vent valve, Cracked or damaged charcoal canister. The specific cause varies by vehicle.
How much does it cost to fix P0455 on a Toyota?
Published repair estimates on Toyota range from $20 to $2,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0455 on a different make?
View P0455 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.