my 96 lancer EL was checked by the casa. sabi kelangan overhaul kasi di na gumagana yung isang piston. pag tinanggal yung hi-tension wire ng sparkplug#3, hindi nagbabago yung andar, that means lost compression(?). nagpalit ng hi-tension wire and sparkplug, ganun pa rin.

help! any other possible reasons for this? mga magkano kaya repair at san maganda magpagawa?