having the harness would be nice but not necessary. you can find compatible plugs for the egr and use those. since you already are wired for vtec you would just have to wire the 5-wire o2 sensor after that. here is a link with pictures of what the egr plugs look like http://www.gassavers.org/showthread.php?t=1546, you'll have to scroll a few images down. Search "d15z1" on that site and you will find a ton of info.