My buddy and I both have a 2001 Mitsubishi Spyder GT. I was driving my buddies the other day after installing new headlights for him and noticed that it has a power surge when accelerating. When at an idle it seems fine but when accelerating hard I noticed all the interior lights and headlights start dimming and brightening. This doesn't happen if accelerating at a normal rate... It only happens when hitting the gas a little on the hard side. Check engine light is not on and no codes. What could this be?