P0457 on Jeep
Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)
P0457 on Jeep vehicles indicates evaporative emission system leak detected (fuel cap loose/off). Au7o has documented this code across 1 Jeep model — most commonly on Wrangler. This code means the engine computer detected a large leak in the sealed fuel-vapor (EVAP) system, most often traced to a loose, missing, or poorly sealing gas cap. The EVAP system is supposed to trap gasoline vapors and burn them in the engine instead of releasing them into the air; a big leak lets those vapors escape. It is an emissions-only fault that will not hurt the engine, though it triggers the check-engine light and can cause a faint fuel smell. Typical repair costs on Jeep range from $25 to $450, depending on the specific model and root cause.
Common Causes of P0457
- •Loose, missing, or improperly tightened fuel cap
- •Worn or cracked fuel cap seal/gasket
- •Damaged fuel filler neck or sealing surface
- •Cracked or disconnected EVAP hose
- •Stuck-open purge or vent valve
- •Faulty fuel cap that won't hold pressure
- •Leaking charcoal canister
P0457 on Jeep by Model
Jeep Wrangler(1 issue)
- EVAP Leak Detection Pump / ESIM Module Failure Triggers P0455, P0456 & P0457 (Often Misdiagnosed as Gas Cap)2007-2018
The JK-generation Jeep Wrangler uses Chrysler's Natural Vacuum Leak Detection (NVLD) approach for its evaporative emissions (EVAP) system, implemented through a leak detection device commonly called the ESIM (Evaporative System Integrity Module) or leak detection pump (LDP). Rather than an active vacuum pump, this module monitors natural temperature-induced pressure/vacuum changes in the fuel/EVAP system to confirm the system is sealed. The ESIM is a known, high-frequency failure point: its internal diaphragm/seal hardens or cracks (or the housing cracks), causing the ECM to falsely detect an EVAP leak even when the system is actually sealed. The result is a check-engine light and one of several EVAP leak codes. Because the very first thing the code points the owner toward is the fuel cap, this failure is routinely misdiagnosed: owners (and shops) replace the gas cap one or more times, the light returns, and the actual culprit is the cheap ESIM/leak-detection module bolted to the charcoal canister. The module is a small white rectangular unit that twists/mounts onto the EVAP charcoal canister, located beneath the vehicle near the fuel tank / just ahead of the rear axle (driver side on most JKs). It is non-safety, non-drivability affecting, but it will cause a persistent CEL and an emissions/smog-test failure. This affects the 3.8L V6 (2007-2011) and 3.6L Pentastar (2012-2018) JK Wranglers, including 2-door and Unlimited 4-door.
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What does P0457 mean on Jeep?▼
P0457 stands for "Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)." This code means the engine computer detected a large leak in the sealed fuel-vapor (EVAP) system, most often traced to a loose, missing, or poorly sealing gas cap. The EVAP system is supposed to trap gasoline vapors and burn them in the engine instead of releasing them into the air; a big leak lets those vapors escape. It is an emissions-only fault that will not hurt the engine, though it triggers the check-engine light and can cause a faint fuel smell. On Jeep specifically, this code is documented across 1 model.
What causes P0457 on Jeep vehicles?▼
Common causes on Jeep: Loose, missing, or improperly tightened fuel cap, Worn or cracked fuel cap seal/gasket, Damaged fuel filler neck or sealing surface, Cracked or disconnected EVAP hose, Stuck-open purge or vent valve. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0457 on a Jeep?▼
Repair costs on Jeep range from $25 to $450, depending on the specific model and root cause.
Which Jeep models have P0457 documented?▼
Au7o has documented P0457 on 1 Jeep model: Wrangler.