GM EcoTec Standalone Harness – Swap Specialties GM EcoTec Standalone Harness. Base Price: $399 A popular option for Sand Rails, buggies, and anything else you can set a 4cyl into, Swap offers premium Harnesses and ECMs to get the job done. Built with only OEM connectors and TXL wire, we hand build each harness on an actual engine and test it on a dyno to assure proper fitment, function,.. CBM MOTORSPORTS™ 2 ECOTEC STAND ALONE WIRING CBM MOTORSPORTS™ 2 ECOTEC STAND ALONE WIRING HARNESS WITH MEFI™ ECM VER. 5 Product Description: This unit comes with a pulse width modulated IAC, billet IAC insert, and billet bracket for a cable driven 2 throttle body. What makes the MEFI™ 5 system unique is its ability to send and receive data via a CAN BUS system.