Ok, I've searched and still can't seem to find a solution to my problem. I did a 5 speed swap from a 99 F23A1 Accord EX into a 2000 F23A4 Ulev Accord EX. I have a CEL due to primary O2 sensor, no reverse lights, and had to modify cluster for temp gauge to work(99 sending unit different than 00). I've tried the O2 "relay delete/wiring" with no success. I had the 5 speed ECM swapped also. What I'm wondering is do I need an ECM from a 2000 5 speed Ulev in order for things to work? I've heard that if you have a CEL, Vtec will not work. Does anything need to be done between Ulev and non-Ulev engine wiring harness? I'm stomped with all this and need help. Can someone please help/point me in the right direction? I dont wanna fork out $150 for ECM then $80 to reprogram if not neccessary. Thanks!