P0455 on a 2012 Honda Pilot

EVAP Large or Gross Leak Detected

P0455 on a 2012 Honda Pilot 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.

Severity: low Safe to drive (short term) Mid-size SUV 2010-2014 Honda Pilot

Reviewed by MECH AI Editorial · Last verified

What does P0455 mean on a 2012 Honda Pilot?

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 2010-2014 Honda Pilot generation — the symptoms, causes, and diagnostic steps below apply to every model year from 2010 through 2014.

Is it safe to drive a 2012 Honda Pilot with P0455?

In most cases a 2012 Honda Pilot 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 2012 Honda Pilot?

What causes P0455 on a 2012 Honda Pilot?

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 2012 Honda Pilot

  1. 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

  2. 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

  3. 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

  4. 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

  5. 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 2012 Honda Pilot

Owner-reported safety complaints and official recalls filed with the U.S. National Highway Traffic Safety Administration for the 2012 Honda Pilot. Use these to gauge how common a problem is on your specific vehicle before you start chasing Honda Pilot diagnostics.

170 owner complaints
17 involved a crash
3 involved a fire
19 reported injuries
  • ENGINE 35
  • POWER TRAIN 20
  • VEHICLE SPEED CONTROL 17
  • SERVICE BRAKES 28
  • ELECTRICAL SYSTEM 22

9 active recalls

  • AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE Sep 2018

    Honda (American Honda Motor Co.) is recalling certain 2014 Honda Insight and Acura TSX and TSX Wagon, 2014-2015 Honda Crosstour and Pilot vehicles nationwide, as well as certain 2014 Honda FCX Clarity and Fit EV vehicles in Florida, Hawaii, Puerto Rico, Texas, Alabama, Georgia, L…

    NHTSA campaign 18V661000
  • AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE Apr 2018

    Honda (American Honda Motor Co.) is recalling certain 2003-2012 Honda Accord and Pilot, 2010 Accord Crosstour, 2001-2011 Civic, 2002-2011 CR-V, 2003-2004, 2006-2008 and 2011 Element, 2007 and 2009-2013 Fit, 2010-2012 Insight, 2002-2004 Odyssey, and 2012 Ridgeline vehicles. The f…

    NHTSA campaign 18V268000
  • AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE Jun 2019

    Honda (American Honda Motor Co.) is recalling certain 2009-2014 Acura TSX, 2011-2014 TSX Sport Wagon, 2010-2013 ZDX, 2008-2012 Honda Accord, 2010-2011 Accord Crosstour, 2006-2011 Civic and Civic Hybrid, 2008-2010 Civic GX NGV, 2012-2015 Crosstour, 2007-2011 CR-V, 2009-2013 Fit, 2…

    NHTSA campaign 19V502000
  • AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE May 2019

    Honda (American Honda Motor Co.) is recalling certain 2009-2014 Acura TSX, 2011-2013 TSX Sport Wagon, and 2010-2012 ZDX and 2008-2012 Honda Accord, 2010-2011 Accord Crosstour, 2006-2011 Civic, Civic Hybrid and Civic NGV, 2012-2014 Crosstour, 2007-2011 CR-V, 2009-2013 Fit, 2010-20…

    NHTSA campaign 19V378000

How do I fix P0455 on a 2012 Honda Pilot?

About the 2010-2014 Honda Pilot

The 2010-2014 Honda Pilot was commonly sold with the following powertrains: 3.5L V6. Common trims include LX, EX, EX-L, Touring, Elite, TrailSport.

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.

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