we just finshed a LS/VTEC swap into a 94 civic, 2 problems. one is that is throwing a check engine light, when i check it, it is code 1. already tried a different o2 sensor. and the other thing is that it doesnt idle very good. and the tach doesn't work smoothly. its kinda jumping around..

 

could it be the iacv?

 

i figured it out! i plugged in a purge valve and no more cel #1