i have a OBD0 B16a and it seems to be misfiring...it sputters when started and takes a while to warm up without it stalling. when i mash it and get to 7rpm VTEC cuts out and returns at 7500rpm. it idles rough. what could be the problem? my headers are pretty smashed...could that be it? ignition? spark plugs and wires?

any suggestions?