EVAP Off Service – Evaporative Emission Control System

The EVAP Off Service disables the Evaporative Emission Control System logic in the ECU software. The EVAP system is designed to prevent fuel vapors from escaping the tank into the atmosphere by capturing them inside a charcoal canister and periodically purging them into the intake system. Over time, the purge control valve or canister often becomes faulty, triggering DTCs, check-engine lights, and drivability issues.

By deactivating the EVAP logic and related readiness monitors in the ECU, our EVAP Off Service ensures that the vehicle runs smoothly without triggering any emission-related DTCs or MIL lights. This solution is particularly useful when the purge system or tank pressure sensors are physically removed, disabled, or replaced with a custom fuel setup.

When to Use

• After removing or disabling the charcoal canister or purge control valve during tuning or custom builds.
• When the EVAP system causes recurring DTCs such as P0441, P0455, P0456, P0457, or related readiness failures.
• For vehicles converted for motorsport or off-road applications where the EVAP system is unnecessary.
• To eliminate check-engine lights caused by tank pressure or purge flow monitoring errors.

Technical Overview

The EVAP subsystem interacts with multiple ECU components, including:

• Purge control valve (N80 / solenoid) – manages fuel vapor flow from the canister to the intake.
• Tank pressure sensor – detects leaks and verifies system integrity.
• Vent control – releases filtered air into the system during purge operation.

When these components fail or are deleted, the ECU logs error codes and sets the readiness flag to “Not Complete.”
Our calibration safely disables these diagnostic checks while keeping other emission systems (such as O2, cat efficiency, etc.) fully functional.

How It Works

1. Assessment: We review the ECU ID and related DTC structure to identify EVAP dependencies.
2. Calibration: We modify purge, tank pressure, and readiness logic to safely bypass EVAP monitoring.
3. Verification: Once flashed, the ECU operates normally with all non-EVAP systems intact and no DTCs.

Compatibility

EVAP Off Service is supported for most petrol ECUs (Bosch, Siemens/Continental, Delphi, Denso, Magneti Marelli, etc.).
Check the live compatibility database below to confirm availability for your ECU type and version.

Learn more about the Evaporative Emission Control System on Wikipedia.