Modifications to OBD Vehicles
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2004 Ford RV Cutaway, 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, and 2004 Ford Excursion. However, it is still accessible from the selected car via links, so may be relevant.
Modifications or additions to the vehicle may cause incorrect operation of the OBD system. Performance modifications that cause a Ford part to fail may not be covered by the Ford New Vehicle Limited Warranty. Burglar alarms, cellular telephones and CB radios must be carefully installed. Do not install these devices by tapping into or running wires close to powertrain control system wires or components.