Need help guys! Nanginginig ang lancer ko during high speeds from 80 to 100kph. Di naman sya hard starting from cold start usually one click lang sya sa umaga start na. I noticed this problem nung mag pa tune up ako. I had been using iridium spark plugs before my recent tune-up and sabi sa kin nung mechanic dapat daw yung may resistor gamit ko. So pinalitan nung nag patune-up ako and just recently nanginginig na sya at high speeds. Could it be spark plugs or may diperensya na HT wires ako. i will have it serviced tomorrow and i wan't to know from you guys where to start. Thanks.

Details of the car:

Mits Lancer MX 2000, INVECS II tranny.