There's nothing abnormal about any engine mod throwing a CEL... Have you reset your ECU and made sure your vacuum hose is attached properly? To reset your ECU simply disconnect your battery and wait a few minutes then reconnect. Give those a try if you haven't and see if it helps. If the CEL comes back you'll need to take it somewhere and have the engine code read to see what exactly is throwing the CEL.
[Edited by phantasm on Jan 17, 2006 5:46 PM]
[Edited by phantasm on Jan 17, 2006 5:46 PM]