Chillmatic

so in my em1 all of sudden when i step on it the car feels like it wants to move and break loose but doesnt, feels like my old sohc. Just happend randomly, i ran no axle back for like 3 days because the hangers broke and put it back on sat as well as using the k&n recharge kit on my air filter, now the car just doesnt seem to have any *****. just did a tune up in november .. any ideas?