First of all I have swapped in a D15b (JDM) into my 93 DX Hatch. The car runs, but there's still some kinks to work out. We wired up V-Tec and had it working, but when trying to solve some other problems it has stopped working. I am runnin the p28 ECU in the car as well. Now i have a CEL and it's only giving me Code 21. As the car is right now, the MAP sensor from the D15b is in place (they changed from stock MAP sensor to that one, no vacuum hose on the new one). Right now the engine idles at about 1500rpm, but bounces up and down pretty quickly and at a steady rhythm (hovers just around 1500, never drops below about 1450 though). Also after driving for awhile, the car will just shut off. I've been trying to figure this out for awhile now, and I'm hoping someone might be able to help me out with it. I think we're using the O2 sensor off of the old motor. Any ideas? Thanks to whomever offers some help!