does it matter which way the clip goes on the injector? like let's say going from left to right, does it need to be power wire, then ground wire(I don't know much about wiring). Or does it matter?

 

The injector connector will only go on one way but yes the injectors do have polarity... On older nonOBD wiring you'll have the grounds for the injector plugs which are the red wires w/ a black stripe... On OBD1/2 car you'll have the same ground but they'll be yellow w/ a black stripe... The other end of the wiring goes to the ECU for the injector output... Whether you have a nonODB or an OBD1/2 car the wires for those will be yellow, blue, red, and brown.. Hope this helps...