VTECth1s

stock jdm b16 in a 00 ek hatch with I/H/E and skunk2 mani...my friend was smashing on all gears with evryone, reving to 8+..no miss shifts..and granny shifting..btw he smashed on a built b20v integ with his fully loaded ek hatch with 3 people..soon as he finished kickin ***...motors starts bogging..jerks wen pressing on gas and would randomly do it every few secs or so..hmm i feel it might be a fuel system problem or bad spark plugs?...input anyone!?