Replying to Honda problems

to anyone out there that knows about cars can you help me out...i have a 2002 honda accord 4 cylinder with 131000 miles on it (i am the original owner) and i recently put a intake on it and lowered it. now here's my problem, i have NO VTEC anymore like its not working or something when i hit 4 thousand rpms it does not pull ne more just gets real loud even when i put it in neutral it hits 4000 rpm revlimitor when it usto rev out at 6500 to almost 7000. now does any one know what could be or is wrong with it? i am taking it to the shop to get looked at plus have the new parts put on it but im just really curious to what the funk this could be.