P0442 on RAM
Evaporative Emission Control System Leak Detected (Small Leak)
P0442 on RAM vehicles indicates evaporative emission control system leak detected (small leak). Au7o has documented this code across 1 RAM model — most commonly on 1500. 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 RAM range from $30 to $300, 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 RAM by Model
RAM 1500(1 issue)
- P0456 / P0442 EVAP Small Leak — ESIM Pump and Purge Valve / Capless Filler Seal2013-2024
A very common check-engine complaint is EVAP 'small leak' codes P0456/P0442 (and sometimes P0455). On 2013-2020 trucks the usual culprits are the Evaporative System Integrity Monitor (ESIM) pump on the charcoal canister or a failed purge valve; on 2019+ capless-filler trucks the capless fuel-filler seal or the purge valve is the frequent cause. It won't harm the drivetrain but fails emissions testing and is a high-frequency search among owners.
Looking for P0442 on a different make?
View P0442 across all makes →Frequently Asked Questions
What does P0442 mean on RAM?▼
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 RAM specifically, this code is documented across 1 model.
What causes P0442 on RAM vehicles?▼
Common causes on RAM: 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 RAM?▼
Repair costs on RAM range from $30 to $300, depending on the specific model and root cause.
Which RAM models have P0442 documented?▼
Au7o has documented P0442 on 1 RAM model: 1500.