P0455 on a 2017 Toyota 4Runner
EVAP Large or Gross Leak Detected
P0455 on a 2017 Toyota 4Runner indicates evap large or gross leak detected. It usually stays drivable short-term but should be diagnosed promptly. The most common cause is missing, loose, or wrong-fit fuel cap (typically $0–$60). Confirm the root cause before replacing parts.
What does P0455 mean on a 2017 Toyota 4Runner?
P0455 is set when the EVAP system's gross-leak monitor detects an opening approximately 0.090 inches (2.3 mm) or larger — or in many cases, no seal at all. This is the size of a missing gas cap, a disconnected hose, or a failed vent solenoid stuck open. The system cannot hold pressure or vacuum for the calibration period, so the ECM concludes a major leak.
This guide covers P0455 across the 2015-2019 Toyota 4Runner generation — the symptoms, causes, and diagnostic steps below apply to every model year from 2015 through 2019.
Is it safe to drive a 2017 Toyota 4Runner with P0455?
In most cases a 2017 Toyota 4Runner stays drivable for short trips with P0455 active, but diagnose and repair it promptly. This is a low-severity code — ignoring it can lead to further damage or a failed emissions test.
What are the symptoms of P0455 on a 2017 Toyota 4Runner?
- Check Engine Light is illuminated
- Distinct fuel smell, especially after refueling
- Fuel-cap warning message on the dashboard on some vehicles
- No drivability issue
- Vehicle will fail emissions / smog testing
What causes P0455 on a 2017 Toyota 4Runner?
| Cause | Likelihood | Estimated repair (USD) |
|---|---|---|
| Missing, loose, or wrong-fit fuel cap Always check first. A locking gas cap from another vehicle that almost fits is a common source. | Most common | $0–$60 |
| Disconnected or split EVAP hose | Common | $30–$200 |
| EVAP vent valve stuck open (will not seal during the monitor test) | Common | $80–$350 |
| Damaged or rusted-through fuel filler neck | Occasional | $200–$700 |
| Cracked or broken EVAP charcoal canister | Occasional | $200–$600 |
| Damaged O-ring at the fuel pump assembly cover | Rare | $30–$500 |
| Rodent damage to EVAP hoses (parked vehicles) | Occasional | $30–$200 |
How to diagnose this on a 2017 Toyota 4Runner
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Check the gas cap is present and correctly seated
Confirm the cap is the correct OEM cap for the vehicle. Many generic-fit replacement caps look identical but have slightly wrong gasket geometry. Hand-tighten to at least 3 clicks. Some vehicles flag a missing cap as P0455 within one drive cycle.
Tools: None
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Visually inspect the EVAP hoses near the canister
On most trucks and SUVs the EVAP canister sits behind the rear bumper or above the rear axle. Inspect every hose from the canister to the tank vent and to the purge solenoid. Pay particular attention to rodent damage on parked vehicles.
Tools: Floor jack and stands, Flashlight
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Smoke-test the EVAP system at low pressure
Introduce smoke at 0.5 psi through the service port. With a large leak the smoke will pour visibly from the failure point within seconds. If smoke escapes from the vent solenoid even with the solenoid commanded closed, replace the solenoid.
Tools: EVAP smoke machine
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Test the EVAP vent valve function
Disconnect the vent valve and apply 12 V — it should click and close. Hold a hand vacuum pump to one port and verify the valve holds vacuum when energized. A vent valve that does not close fully will set P0455 because the system can never seal.
Tools: 12 V test source, Hand vacuum pump
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Inspect the fuel filler neck and tank-top seals
Rust-belt vehicles often develop pinholes or seam separation in the metal portion of the fuel filler neck. Once the rust is through, the EVAP system cannot hold any vacuum. Replacement is the only fix.
Tools: Floor jack and stands, Inspection mirror
NHTSA complaints & recalls for the 2017 Toyota 4Runner
Owner-reported safety complaints and official recalls filed with the U.S. National Highway Traffic Safety Administration for the 2017 Toyota 4Runner. Use these to gauge how common a problem is on your specific vehicle before you start chasing Toyota 4Runner diagnostics.
- ENGINE 2
- UNKNOWN OR OTHER 13
- SERVICE BRAKES 9
- ELECTRICAL SYSTEM 5
- AIR BAGS 3
5 active recalls
- EQUIPMENT:OTHER:LABELS Oct 2018
Southeast Toyota Distributors, LLC (SET) is recalling certain 2017-2019 Toyota 4Runner vehicles that SET modified to be equipped with a TRD wheel package. The Gross Vehicle Weight Rating (GVWR) on the certification label may be incorrect, possibly resulting in the vehicle being…
NHTSA campaign 18V753000 - EQUIPMENT:OTHER:LABELS Dec 2017
Toyota Motor Engineering & Manufacturing (Toyota) is recalling certain 2017-2018 Toyota 4Runner and Tundra, 2018 Toyota Highlander, RAV4 and Lexus GX460 and 2017 Toyota Sienna and Tacoma vehicles. These vehicles may have incorrect load carrying capacity modification labels. As…
NHTSA campaign 17V831000 - STRUCTURE:BODY:HOOD Nov 2017
Southeast Toyota Distributors, LLC (SET) is recalling certain 2015-2018 Toyota 4Runner vehicles equipped with an accessory Billet Grille Overlay installed by SET or provided by SET and installed by SET dealers. The U-nut that secures the overlay grille may fracture, allowing the…
NHTSA campaign 17V763000 - TIRES:TEMPORARY/EMERGENCY SPARE TIRE May 2017
Gulf States Toyota, Inc. (Gulf States) is recalling certain 2017 4Runner , 86, Avalon, Camry, Camry Hybrid, Corolla, Corolla iM, Highlander, Highlander Hybrid, Prius, Prius C, RAV4, RAV4 Hybrid, Sienna and Yaris vehicles. The spare tire air pressure was not adjusted to the prop…
NHTSA campaign 17V295000
How do I fix P0455 on a 2017 Toyota 4Runner?
- Replace the fuel cap
- Replace the EVAP vent valve / vent solenoid
- Replace damaged EVAP hoses
- Replace the EVAP charcoal canister
- Replace the fuel filler neck
About the 2015-2019 Toyota 4Runner
The 2015-2019 Toyota 4Runner was commonly sold with the following powertrains: 4.0L V6. Common trims include SR5, TRD Off-Road, TRD Pro, Limited.
How fast P0455 sets after a missing cap
Most OBD-II vehicles flag P0455 within one cold-start drive cycle after the cap is left off. Some Ford and GM vehicles will set a more specific “check fuel cap” message first and only escalate to P0455 if the issue persists across multiple drive cycles.
P0455 right after winter on a parked vehicle
Mice and rats chew EVAP hoses to nest inside the canister or near the fuel tank. If P0455 appears on a vehicle that has been parked for the winter, inspect every accessible EVAP hose for clean-edged bite marks before buying parts. This pattern is so common on rural-parked trucks that several shop forums have dedicated threads.
The cap that “fits” but doesn’t seal
A locking gas cap from a similar-vintage vehicle in the same brand family often threads on but seals against the filler neck at the wrong depth or angle. The result is repeated P0455 codes after every refuel. If the cap has been replaced and the code persists, double-check it is the exact OEM part number for this vehicle.
P0455 on a 2017 Toyota 4Runner: frequently asked questions
What does diagnostic trouble code P0455 mean on a 2017 Toyota 4Runner?
P0455 is set when the EVAP system's gross-leak monitor detects an opening approximately 0.090 inches (2.3 mm) or larger — or in many cases, no seal at all. This is the size of a missing gas cap, a disconnected hose, or a failed vent solenoid stuck open. The system cannot hold pressure or vacuum for the calibration period, so the ECM concludes a major leak.
What are the symptoms of P0455 on a 2017 Toyota 4Runner?
Check Engine Light is illuminated. Distinct fuel smell, especially after refueling. Fuel-cap warning message on the dashboard on some vehicles. No drivability issue. Vehicle will fail emissions / smog testing
What causes P0455 on a 2017 Toyota 4Runner?
Missing, loose, or wrong-fit fuel cap (most-common). Disconnected or split EVAP hose (common). EVAP vent valve stuck open (will not seal during the monitor test) (common). Damaged or rusted-through fuel filler neck (occasional). Cracked or broken EVAP charcoal canister (occasional). Damaged O-ring at the fuel pump assembly cover (rare). Rodent damage to EVAP hoses (parked vehicles) (occasional)
Is it safe to drive a 2017 Toyota 4Runner with P0455?
In most cases a 2017 Toyota 4Runner stays drivable for short trips with P0455 active, but it should be diagnosed and repaired promptly — this is a low-severity code. Ignoring it can lead to further damage or a failed emissions test.