It wouldn't run at its potential and could potentially cause serious engine damage (ie fried piston rings). I ran the Greddy equivalent for over a year with minimal problems but the engine felt so much stronger when I upgraded to Crome. It probably just splices into the MAP, injector, power and ground wires at the ECU and piggybacks off it. It shouldn't take more than 20 minutes to install assuming you know how to use a soldering iron and know which wires are which.