P0455 on a 2017 Jeep Wrangler

P0455 means the EVAP system failed a leak check badly enough that the computer sees a large leak or no pressure/vacuum change.

Not your vehicle? See general P0455 info.

Most common causes on the 2017 Jeep Wrangler

Ranked from 304 NHTSA owner complaints filed for this vehicle.

Sort by:

1
Fuel tank vent/pressure control valve failure causing overfill and vapor leaks
High severity
Multiple owners had a diagnosed crack or inoperative fuel tank control/vent valve letting vapor escape and fuel overflow at fill-up, including one report of chronic filler-tube overflow every fill — a large enough leak to trip the large-leak monitor.
Reported in 4 NHTSA complaints
Parts:fuel tank vent valve filler neck
2
Loose, missing, or damaged gas cap
Low severity
P0455 is a LARGE-leak code, and one owner's recurring fuel-cap light and two cap replacements shows the cap was at least a contributing seal failure.
Reported in 1 NHTSA complaint
Parts:gas cap
3
Fuel sending unit/tank assembly defect
Medium severity
Owner cites FCA recall campaign 16V849 for a defective fuel sending component on 2017 Jeeps, indicating a known tank-assembly manufacturing defect that can leak.
Reported in 1 NHTSA complaint
Parts:fuel level sending unit
4
Rusted or corroded fuel filler neck
Medium severity
Filler-neck corrosion is a common large-leak source in older Wranglers.
Common cause
Parts:filler neck
5
Cracked or disconnected EVAP hose/line
Medium severity
A fully split or popped-off line produces a leak large enough to fail the large-leak monitor.
Common cause
Parts:evap hose
6
Cracked charcoal canister
Medium severity
A split canister housing is a large enough opening to set a P0455.
Common cause
Parts:charcoal canister

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These causes are aggregated from NHTSA owner complaints and general repair knowledge — this is not a diagnosis. P0455 on your car still needs shop confirmation before any repair.

Common symptoms

Check engine light
Fuel smell
Usually no performance issue
Failed emissions readiness

What to check before replacing parts

Check the gas cap first

Look for: A loose, missing, or cross-threaded cap is by far the most common cause of a large EVAP leak code — if it doesn't click to full tightness or the seal is cracked, that's very likely the whole fault.

Inspect visible EVAP hoses

Look for: A large leak is often obvious: a hose disconnected at a fitting, split open, or chewed through (rodent damage is common) rather than a hairline crack.

Command the purge and vent valves with a scan tool

Look for: A valve that doesn't respond at all when commanded open/closed, or stays open when it should seal, prevents the system from holding pressure/vacuum and reads as a large leak.

Smoke-test the system

Look for: With a large leak, expect an obvious plume of smoke or a clearly audible hiss at the fault location — it should be easy to spot compared to a small-leak diagnosis.

Inspect the canister and filler neck

Look for: A cracked charcoal canister housing or a corroded/rusted-through filler neck (common on older vehicles) can leak enough to prevent the system from ever holding vacuum.

Rather have a pro handle it? Find a vetted local mechanic.

Matching symptoms

Check Engine Light