Idle dropping a bit after exhaust install..

[s14joe]

Yesterday I installed the Apexi N1 exhaust and after driving for a while I noticed my RPM's dipping slightly. I intially thought it was in conjunction w/ the exhaust install. However, after more driving today I basically ruled out the exhaust theory. I noticed that drops in RPM's for a sec when:

1.press the brakes-----------requires vacuum2.put on the air--------requires engine power + electricity3.put my headlights on/foglights--------requires electricity

Can anyone add some insight on what is going on?

Thanks

~Joe

[stillmatic]

I believe that's normal.

My friend told me that every car misfires when you step on the brakes. Well, at least my 240, his Integra, and his dad's celica does.