I'm not sure if I've just never noticed this before or if it just came out of nowhere but, I can feel a random pulsing feeling coming from the engine that doesn't really seem to have any ordered pattern. I only feel this with the headlights and A/C turned OFF.

Having the headlights or A/C turned on makes the pulsing almost impossible to feel.

I'll come to a stop, the car will feel completely still for a few seconds, and then I start feeling the pulsing.

No CEL, car pulls strong as before when redlining.

MODS:Engine torque dampener, 4.77, k&n intake

Any ideas?