Crome is a ROM editing and tuning suite for OBD1 Honda ECUs. While the base software supports standard fuel and ignition tables, advanced features—such as launch control, full-throttle shifting (flat foot shift), and boost scaling—are implemented via the Add Extra Features (addextrafeatures.cpf) plugin.

Prerequisites#

• A valid OBD1 .bin file (e.g., P28, P30, or P72 base map).
• The addextrafeatures.cpf plugin file.

1. Plugin Installation#

Crome requires plugin files to be placed in the local installation directory to be recognized by the software.

1. Extract the addextrafeatures.zip package.
2. Copy the addextrafeatures.cpf file to the Crome plugins directory.
   • Default Path: C:\Program Files (x86)\Crome\Plugins\

Note

If the archive is password-protected, use the standard Crome distribution password to extract the contents.

2. Registering the Plugin#

Once the file is placed in the directory, it must be registered within the Crome interface.

1. Launch Crome.
2. Navigate to Plugins > Install New Plugin...
3. Select addextrafeatures.cpf from the Plugins directory.
4. Click Open.
5. Verify the plugin is active by checking the Plugins menu.

3. Patching the ROM#

After registration, the plugin must be applied to the specific ROM file to inject the necessary code.

1. Open your target OBD1 .bin file in Crome.
2. Navigate to Plugins > Enhancements > Add Extra Features.
3. Follow the wizard prompts and click Next to execute the code injection.
4. Once the process completes, the new parameters will be available in the ROM.

Important

Always save a backup copy of your original .bin file before applying patches.

4. Configuration#

After patching, the new features will appear in the Crome interface.

• Parameter Access: Navigate to the Options menu or the newly created table tabs to adjust specific values.
• Common Features:
  • Launch Control: Set the RPM limit for stationary launches.
  • Flat Foot Shift: Define the RPM window for full-throttle gear changes.
  • Boost Scaling: Adjust maps to accommodate forced induction sensors and pressure targets.

Tip

After configuring new features, verify the checksum of the ROM before uploading to the ECU to ensure the file integrity remains intact.