Download 1) Removing the Stock Engine Control Unit a) Access the stock Engine Control Unit (ECU). The location of the ECU on the RX- 7 is in the passenger fenderwell. b) Carefully disconnect the wiring harness from the ECU. Avoid excessive stress or pulling on the wires, as this may damage the wiring harness. Some factory ECU’s use a bolt to retain the factory connectors, and it must be removed before the harness can be disconnected. There may be more than one connector, and they must all be removed without damage to work properly with the AEM ECU. Do not cut any of the wires in the factory wiring harness to remove them. c) Remove the fasteners securing the ECU to the car body, and set it aside. Do not destroy or discard the factory ECU, as it can be reinstalled easily for street use and troubleshooting. 2) Install the AEM Engine Management System. a) Plug the factory wiring harness into the AEM ECU, and position it so that the wires are not pulled tight or stressed. Secure it with the provided Velcro fasteners. b) Plug the comms cable into the EMS and into your PC. c) Turn your ignition on but do not attempt to start the engine. d) Upload the base calibration file (.cal) that most closely matches your vehicle’s configuration.