Look at your existing (original) oxygen sensor. For the '93 four cylinder there should be one wire at the primary sensor. To the best of my knowledge, the original sensor is unheated. I always like to use original equipment, but you can always shop for price and often do much better than the local dealer. Use your VIN number when ordering so they can be sure to select the correct part for your vehicle. O2 sensors need to be hot before generating a signal, so the addition of a heating filament helps them heat up more quickly thus saving some fuel when first starting up. However, the most common failure mode is for the heating element to burn out over time, whereas if the unheated O2 sensor remains free of contamination, they can last quite a long time.