no exhaust smoke either

 

With this kind of problem you should be getting a code. Have you scaned it?

 

thanks for all your reply's, i found out what was wrong. I installed a HID conversion kit on saturday and i had to remove the airbox in order to mount the ballasts. Turns out that i did not fully tighten the hose-clamp that holds the hose to the engine. it had half slipped off and was causing this. Put it back on and car runs fine now. Yes i am embarrased and i went into panic mode thinking that i would be dishing out lots of money in order to fix this. Thanks again for your quick reply's