You can get a universal 4-wire O2 and wire it onto your stock harness if you don't want to pay for an OEM one. Just make sure you get the signal, signal ground, and heater wires right, or else it won't work right. I have an OEM primary O2 that has its harness extended if you need one. The extension is pretty long, but you can cut it off and shorten it if you want.