Really bad idle after leaving the battery disconnected?

I disconnected the battery while I was taking the interior out, hooked it back up a couple of times just so I could lock up the car.

Installed a new air filter today, started up the car and it has a really bad idle when it did not have any issues before. I checked all connections to the airbox but what else should I check?

When I blip the throttle the response is horrible, in fact the car almost wants to stall if I open up the throttles too fast.

I removed the intake, checked the elbow for cracks, put it all back together, hooked it up, started the car and now it idles fine.

So not sure exactly what I did to fix the problem but it allowed me to balance the throttle bodies as planned.