taking off

[dak2007]

:ylsuper ok here it goes. my car just recently, well after taking off the box surounding the airfilter, wants to act funny until i drive it for a couple of minutes. at the stop signs it was to kind of shake just a lil bit and the rpm's move just a lil. it's almost as if one of the spark plugs has come lose. could this be the aiv? if so should i take it off? if i did take it off would it increase speed, hp, power, gas mileage? :spam