If you're installing a Gen IV Chevy LS engine into a hot rod, street machine or any non-EFI vehicle and want to retain the LS engine's OEM electronic fuel injection system, the new Pro-Flo 4 LS ECU & Harness Kit #35712 is what you'll need to complete the installation and get your Gen IV LS up and running to its full potential. This kit is designed specifically for the Gen IV LS engine with a 58X reluctor identified by the gray camshaft sensor mounted in the timing cover. The compact ECU and harness integrate seamlessly with the existing LS injectors, coils, camshaft/crank sensors and other factory intake manifold connections to greatly simplify the installation, start-up and performance tuning processes. This kit provides the perfect solution for those "junkyard" LS engine swaps where the factory ECU and wiring harness may be missing or damaged. The Gen IV LS ECU & Harness Kit #35712 can be used for any level of LS performance, and what makes this kit so unique and easy to use is the Edelbrock E-Tuner application, which eliminates the need for laptop tuning or costly dyno sessions. The E-Tuner is a user-friendly app that uses Bluetooth connectivity to communicate with the ECU and comes pre-installed for you in the kit's included Android-based tablet. You can also download it free of charge in the Google Play Store to use with your Android-based smartphone. The key to the E-Tuner's simplicity is a Setup Wizard that guides you step by step through the initial programming for your particular engine. Once you provide the Setup Wizard with basic data (type of engine, cubic inches, firing order, cam profile), the E-Tuner then selects the most appropriate base calibration for your engine. As you drive the vehicle, the self-learning E-Tuner continually maximizes the fuel map according to the environment and your driving style so that your engine is always performing at its best.