P0456 on a 2022 Toyota Camry
EVAP Very Small Leak Detected
What does P0456 mean on a 2022 Toyota Camry?
P0456 is set when the EVAP system's very-small-leak monitor detects an opening approximately 0.020 inches (0.5 mm) or larger. This is finer than P0442 (0.040") and significantly harder to find — it can be a single pinhole, a hardened O-ring, or a hairline crack in a plastic component. The vehicle drives normally and there is rarely any fuel smell.
Symptoms on a 2022 Toyota Camry
- Check Engine Light is illuminated
- Almost never any drivability complaint
- Rarely any noticeable fuel smell (leak is too small)
- Vehicle will fail emissions / smog testing
Likely causes on a 2022 Toyota Camry
- Worn fuel cap O-ring or wrong-spec cap Most commonEstimated repair: $15– $60
- Aged or cracked EVAP hose elbows and quick-connect O-rings CommonEstimated repair: $30– $200
- Hairline crack in the charcoal canister body CommonEstimated repair: $200– $600
- Leaking EVAP purge valve seat (small internal leak only) OccasionalEstimated repair: $80– $300
- Fuel tank pressure sensor O-ring hardened OccasionalEstimated repair: $30– $150
- Pinhole at the fuel tank top — visible only with smoke or dye RareEstimated repair: $300– $1,200
How to diagnose this on a 2022 Toyota Camry
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Replace the fuel cap with a fresh OEM-spec cap
A 0.020" leak at the cap costs $30 to rule out. Hand-tighten until the cap clicks at least 3 times. Drive several drive cycles so the monitor reruns. Many P0456 codes never come back after this step.
Tools: None
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Smoke-test at the lowest pressure your machine supports
P0456 leaks are at the threshold of what smoke machines can find. Use the lowest pressure setting (0.5 psi or less). Let smoke build for 10 minutes. Inspect every quick-connect, O-ring, hose elbow, and canister seam with strong light. UV dye in the smoke fluid helps trace very faint trails.
Tools: EVAP smoke machine with UV dye, UV flashlight, Magnification glass
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Read mode 6 EVAP test results
Mode 6 will show the recorded leak-decay rate from the last test. If the failure threshold is just barely exceeded, the leak is at the very small end — often a hardened O-ring or aged plastic. If the threshold is wildly exceeded, P0455 would normally set instead; P0456 with a large mode-6 deviation suggests the monitor calibration is off.
Tools: Scan tool with mode 6 support
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Test the purge valve for an internal leak
Apply vacuum to the inlet side of the purge valve with the valve de-energized — it should hold vacuum indefinitely. A valve that slowly leaks vacuum is allowing fuel vapor through during engine-off, which the monitor sees as a system leak.
Tools: Hand vacuum pump
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Verify the readiness monitor before re-testing
After any P0456 repair, drive 4–6 cold-start cycles with the tank between 25 % and 75 % full. Confirm the EVAP readiness monitor shows "complete" on the scan tool. A vehicle that passes a state smog test with the monitor "not ready" will not actually pass — most states fail vehicles with incomplete monitors.
Tools: Scan tool with readiness display
Known Technical Service Bulletins for the 2020-2024 Toyota Camry
Manufacturers publish Technical Service Bulletins (TSBs) when a known issue affects a specific vehicle. These bulletins come from the NHTSA database for your Toyota Camry.
- ENGINE Feb 26, 2026
OBSOLETE NOTICE February 27, 2026: This bulletin is no longer applicable and is now obsolete.
NHTSA #11029896 - ELECTRICAL SYSTEM Jan 29, 2026
OBSOLETE NOTICE January 30, 2026: This bulletin is now obsolete. Please see T-SB-0001-26.
NHTSA #11028726 - ELECTRICAL SYSTEM Jan 27, 2026
Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool (SST) USB flash drive to update the map, points of interest, and system software.
NHTSA #11028722 - UNKNOWN OR OTHER Jan 6, 2026
Some 2005 – 2026 Toyota vehicles that have undergone water intrusion may exhibit a condition in which a musty odor is present. Follow the procedures in this bulletin to remediate the odor and address this condition. The purpose of this Service Bulletin is to provide general guidelines and procedures for odor remediation. This Service Bulletin provides a guide on how to prepare and treat the interior of the vehicle for odor remediation. Refer to the applicable model and model year Repair Manual and the EPA (Environmental Protection Agency) website for the most up-to-date safety and precautionary guidelines.
NHTSA #11028712 - ENGINE Aug 6, 2025
The specific condition covered by this program is for a small engine coolant leak that can occur from the flow shut-off valve that can allow coolant to drip on other parts of the vehicle. This can cause "Engine Maintenance Required" to be displayed on the instrument cluster or cause the A/C not to function normally. Although the flow shut-off valve is covered by Toyota’s New Vehicle Limited Warranty for 36 months or 36,000 miles (whichever comes first), we at Toyota care about the customers’ ownership experience. Toyota is providing coverage for repairs related to Flow Shut-off Valve Coolant Leak.
NHTSA #11022949 - ELECTRICAL SYSTEM Jun 24, 2025
Some 2021 – 2022 model year Avalon, 2018 – 2024 Camry, 2019 – 2025 model year Corolla, 2022 – 2025 model year Corolla Cross, and 2019 – 2025 model year RAV4 vehicles with A25A-FKS and M20A-FKS engines may have a MIL ON condition with one or more of the following Diagnostic Trouble Codes (DTCs) upon cold soak start up with engine coolant temperatures between 14°F – 41°F: •P030027 – Random/Multiple Cylinder Misfire Detected (Emission) Signal Rate of Change Above Threshold •P030000 – Random/Multiple Cylinder Misfire Detected •P030100 – Cylinder 1 Misfire Detected •P030200 – Cylinder 2 Misfire Detected •P030300 – Cylinder 3 Misfire Detected •P030400 – Cylinder 4 Misfire Detected
NHTSA #11020670
+14 more TSBs available in MECH AI's TSB explorer for this vehicle.
Common fixes
- Replace the fuel cap
- Replace cracked EVAP hose elbows and aged O-rings
- Replace the EVAP charcoal canister
- Replace the EVAP purge valve
- Replace the fuel tank pressure sensor or its O-ring
About the 2020-2024 Toyota Camry
The 2020-2024 Toyota Camry was commonly sold with the following powertrains: 2.5L I4, 3.5L V6, 2.5L Hybrid I4. Common trims include LE, SE, XLE, XSE.
Why P0456 is the hardest EVAP code to diagnose
A 0.020-inch leak is roughly the size of a sewing needle hole. At atmospheric pressure that is essentially invisible. The only practical way to find it is with a smoke machine, UV dye, and patience — every joint, every gasket, every plastic seam. Shops typically charge a $100–$200 diagnostic fee for P0456 because the inspection takes 30–60 minutes even when you find the leak quickly.
P0456 vs. P0442
Same EVAP system, different leak-size threshold:
- P0442 ≈ 0.040” leak. Often a loose gas cap or visibly cracked hose.
- P0456 ≈ 0.020” leak. Almost never visible. Smoke-test mandatory.
A vehicle that previously set P0442 and now sets P0456 has had a leak get smaller — usually because someone tightened a cap or replaced a hose but missed the real source.
When the code keeps coming back
If P0456 returns within 30 days of a repair, the leak was not actually fixed — the monitor simply did not run again in the interim. Common overlooked sources: the spare-tire-mounted tank vent on certain trucks, the canister filter housing, and the seam where the fuel tank meets the filler neck on rust-belt vehicles.