First off what model is the hatchback I know for sure the 92CX came prewired vtec from the ecu to the shock tower. DO NOT "tap" into any wires. That is ghetto! Do it right the first time. Pherable.net has great color illustrations for you to look at figure out what you need to do. Ideally you would want to use a Obd1 Civic EX harness because it will be plug-n-play. Complete with necessary vtec wires and a 4 wire o2 sensor.