Maybe during installation you accidentally bumped the spark plug wires on the distributor, hence crappy, rich idling from a cylinder not getting a full spark. At first I was thinking maybe a sensor was unplugged but you said no CEL. Try resetting the ECU. The car should still run fine even if there was no intake on at all. Even if the hoses that connect to the intake pipe are off, it should run. Is there gas in the car? What other mods do you have?