Where do I install a performance chip on the ECU for a 1990 Mazda Miata?

I have a 1990 Mazda Miata and i want to install a performance chip in it but i don't know where to attach the 2 wires from the chip to the ecu, can someone please be specific and explain to me how to put it in, ThanksWhere do I install a performance chip on the ECU for a 1990 Mazda Miata?
Those 2 wire chips do not work. All they do is make your cars fuel injection run rich by changing the readings the computer receives. So it ruins you gas mileage. No matter what you was told by who ever sold it to you. They are junk and that chip you gave big money for can be bought at Radio Shack for less than a dollar. Don't waste your time and send it back if they allow it.........mdWhere do I install a performance chip on the ECU for a 1990 Mazda Miata?
Send it back . Its just a resistor. Not going to make your car run any better then it does when you first start it. If you want to do some homework... Learn about OBD 1 fuel injection.