P0442 on Jeep
Evaporative Emission Control System Leak Detected (Small Leak)
P0442 on Jeep vehicles indicates evaporative emission control system leak detected (small leak). Au7o has documented this code across 2 Jeep models — most commonly on Grand Cherokee, Wrangler. This emissions code means the evaporative emission (EVAP) control system has detected a small leak. The EVAP system seals the fuel tank and captures gasoline vapors, routing them to be burned in the engine instead of escaping into the air, and the computer periodically pressure- or vacuum-tests the system to confirm it's sealed. A small leak the size of about a 0.040-inch hole will set this code. By far the most common and cheapest cause is a loose, damaged, or missing gas cap, so that's the first thing to check, though any cracked hose or worn seal in the system can also trigger it. Typical repair costs on Jeep range from $25 to $350, depending on the specific model and root cause.
Common Causes of P0442
- •Loose, damaged, or missing fuel filler cap
- •Worn or cracked gas cap seal
- •Cracked or disconnected EVAP hose or line
- •Faulty purge valve or vent valve
- •Damaged O-ring or seal at the fuel tank or filler neck
- •Small crack in the charcoal canister
- •Leaking fuel tank sending unit gasket
P0442 on Jeep by Model
Jeep Grand Cherokee(1 issue)
- P0442 — Small EVAP Leak from Failed ESIM or Degraded Gas Cap Seal2011-2021
P0442 (small EVAP leak, roughly a 0.020–0.040 inch pinhole) is very common on the WK2 Grand Cherokee. The two dominant causes are a degraded gas cap rubber seal and, specific to this platform, a failed Evaporative System Integrity Module (ESIM) mounted in the rear driver-side wheel well. The ESIM is a well-documented WK2 failure point and often fails before other EVAP components; it is known to pass a smoke test yet still set the code because its internal switch fails to report the correct state to the PCM. A vapor canister purge valve stuck slightly open is a secondary cause. There are typically no drivability symptoms beyond the check engine light, and the code can be intermittent (may clear after a few good drive cycles once the cap is tightened).
Jeep Wrangler(1 issue)
- P0442 — Small EVAP Leak from Loose Gas Cap or Cracked Canister Vent Hose2007-2021
P0442 on the Wrangler flags a small (~0.020-0.040 in) leak in the evaporative emissions system. On these Jeeps the two most common real-world sources are a loose, worn, or cracked fuel cap seal and a cracked rubber elbow/vent hose at the charcoal canister near the rear of the vehicle. Wranglers see a lot of trail dust, water crossings, and vibration, which ages the small rubber EVAP elbows and the o-ring on the fuel cap. Less commonly the purge valve, leak-detection pump, or the filler neck itself is the culprit. The code is emissions-only and typically causes no drivability problem, but it will fail an emissions/inspection test.
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What does P0442 mean on Jeep?▼
P0442 stands for "Evaporative Emission Control System Leak Detected (Small Leak)." This emissions code means the evaporative emission (EVAP) control system has detected a small leak. The EVAP system seals the fuel tank and captures gasoline vapors, routing them to be burned in the engine instead of escaping into the air, and the computer periodically pressure- or vacuum-tests the system to confirm it's sealed. A small leak the size of about a 0.040-inch hole will set this code. By far the most common and cheapest cause is a loose, damaged, or missing gas cap, so that's the first thing to check, though any cracked hose or worn seal in the system can also trigger it. On Jeep specifically, this code is documented across 2 models.
What causes P0442 on Jeep vehicles?▼
Common causes on Jeep: Loose, damaged, or missing fuel filler cap, Worn or cracked gas cap seal, Cracked or disconnected EVAP hose or line, Faulty purge valve or vent valve, Damaged O-ring or seal at the fuel tank or filler neck. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0442 on a Jeep?▼
Repair costs on Jeep range from $25 to $350, depending on the specific model and root cause.
Which Jeep models have P0442 documented?▼
Au7o has documented P0442 on 2 Jeep models: Grand Cherokee, Wrangler.