Pre98 Contours use "Return" style injectors.
Post98 Contours use "Returnless" style injectors.
Return is for fuel sytems that have a fuel line that returns excess fuel to the fuel tank.
Returnless is, take a wild guess, for fuel systems taht do not return fuel.
The wirining harness connector is different between the two style injectors.
You'll have to splice in new connectors on the injector harnes.
