i just put in a new k&n filter, with the mariah motorsports cold airbox, hooked up all the hoses, clamped down the clamps, ran the new hose to the air pump, when i first started it, the car started fine. drove it around, after around 2 miles, when i stopped at a stop sign, it started to idle weird. it would drop to 1500 rpms, then back up to 2000 rpms, and keep doing it like revving the engine, then off, then on, then off...etc.

i dont know if when it is idling if its not getting enough air..or what going on?

 

Sounds like a vac leak to me.