Trouble Code Trouble

Ok, here's the thing. I just sold my 95' GSR and put a deposit on a 98' Prelude Type SH. Well the Lude is nice and everything except the check engine light is on. The owner showed me the reciept from the mechanic that did a bunch of work on it. Well I guess they can't figure out why the light is on. He said that it isn't throwing any code's and that the VTEC is still working. And that it's probably because of the DC header or the cold air intake that's installed on the vehicle. But I just have a hard time believing that. I mean from past experience with my GSR, whenever the check engine light is on, you automatically won't have VTEC engagement. So how is a Prelude different? Any and all help would be very appreciated.