P0440: Evaporative Emission Control System Malfunction
18 vehicles · 10 makes · $15-$2,500 repair
Most Reported On
P0440 is an OBD-II diagnostic trouble code meaning “Evaporative Emission Control System Malfunction.” This code indicates a general malfunction in the Evaporative Emission Control (EVAP) system, which captures fuel vapors from the gas tank and routes them to be burned by the engine instead of escaping into the air. The computer ran a self-test and detected the sealed vapor system isn't holding pressure or vacuum correctly, often signaling a leak somewhere in the system. The most frequent and easiest cause is a loose or faulty gas cap. The car will run normally, but it will fail an emissions test and may smell faintly of fuel. This code is most commonly reported on 2011-2023 Chrysler 300, 2007-2014 Toyota FJ Cruiser, and 2016-2023 Toyota Tacoma, plus 15 other vehicles, with repair costs ranging from $15 to $2,500.
Common Causes
Typical Repair Cost
Based on 21 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0440, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (18)
AC Compressor Failure and Evaporator Leaks
EVAP Leak Detection (ESIM/NVLD) Module Failure Triggers False P0455/P0456 Codes
Fuel Tank Hard to Fill / Nozzle Clicks Off Repeatedly (EVAP Venting)
EVAP Leak Detection Pump (ESIM) Failure Causes Persistent P0455/P0456 — Often Misdiagnosed as a Gas Cap
A/C Compressor and Evaporator Failure
A/C Musty/Mold Smell
EVAP Purge Valve / Charcoal Canister Failure — P0441 / P0455 & Fuel-Pump Click-Off
EVAP Charcoal Canister and Vent Valve Failure Causing Check Engine Light
Evaporative Emissions Leak Faults from Charcoal Canister, Vent Valve, or Filler Neck Corrosion
EVAP System Leak — Charcoal Canister / Vacuum Switching Valve (VSV) Failure (P0440 / P0441 / P0446)
FAQ
What does P0440 mean?
P0440 stands for "Evaporative Emission Control System Malfunction." This code indicates a general malfunction in the Evaporative Emission Control (EVAP) system, which captures fuel vapors from the gas tank and routes them to be burned by the engine instead of escaping into the air. The computer ran a self-test and detected the sealed vapor system isn't holding pressure or vacuum correctly, often signaling a leak somewhere in the system. The most frequent and easiest cause is a loose or faulty gas cap. The car will run normally, but it will fail an emissions test and may smell faintly of fuel.
What are the most common causes of P0440?
The most common causes of P0440 are: Loose, damaged, or missing gas cap, Cracked or disconnected EVAP hose, Faulty purge valve/solenoid, Faulty vent valve/solenoid, Leaking charcoal canister, Damaged fuel tank filler neck or seal, Faulty leak detection pump or pressure sensor. The specific cause varies by vehicle.
How much does it cost to fix P0440?
Repair costs for P0440 range from $15 to $2,500, depending on the vehicle and root cause.
Which vehicles are affected by P0440?
Au7o has documented P0440 across 18 vehicle models from 10 manufacturers: Chevrolet, Chrysler, Dodge, Hyundai, Kia, Mazda, Nissan, Pontiac, Subaru, Toyota.
Sources (12)
- ForumReddit r/ToyotaTacoma thread discussing musty smell in 2016 Tacoma A/C
- ForumMazdas247 Forum - 2006 Mazda5 A/C evaporator leak / dash removal discussion
- ForumESIM (Evap System Integrity Module) Installation fixed P0456 code | Dodge Charger Forum
- Forumthrowing code P0456 - evaporative emissions system leak | Dodge Charger Forum
- ForumP0456 evap small leak | Dodge Charger Forum
- ForumCode: P0456 finally Resolved!........$2,500.00 later!!!! (fuel-tank pinhole) | Dodge Challenger Forum
- articleP0456 on 2012-2019 Dodge Charger: EVAP Small Leak Causes and Fixes | Go-Parts.com
- articleP0455 on 2016-2022 Dodge Charger: EVAP Large Leak Causes and Fixes | Go-Parts.com
- articleP0457 Dodge Charger: EVAP System – Leak Detected | Drivetrain Resource
- ForumCarComplaints - Hyundai Elantra Fuel System and Emissions Complaints
- ForumGenVibe — CEL trifecta: P0441, P0442, P0446 (2003-2005 Vibes)
- ForumGenVibe — 2003 Vibe AWD: CEL P0446 SOLVED! (stuck/rusted EVAP vent solenoid valve)
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.