a couple of years ago i got the head, intake, tb and ecu from a 97'hx(vtec-e) for free so i went forth to install it in my 90' rex si. over some time i got a cold air intake, full exhaust, cam gear and ecu convertion harness from rywire. it's all together, working and tweeking but it dosen't seem to want to run with the 97' parts. i tried the 90' intake and tb but the same results. i still need to get a 2nd o2 but would that matter that much?