hi guys, i own a vn s1 1990 v6 commodore, some days it completely hammers and when i do 40k kickbacks it lights the wheels, and other days i boot it, and it feels like im at half throttle, what could this be?? o2 sensors?? i reset computer and it goes back to wheelspin mode haha for like 1 day, then again, sluggy old ladys car mode, and i filled whole tank of premium, and it played up so its not my fuel any suggestions??