more air?

Is it possible to increase power with more air? The other day my air filter housing came open it's a 2001 sable with the duratec. I noticed two things were wrong immediately; 1. the car would not idle. 2. when it was moving it had more power than I thought it could have.

Is there any way to solve the idle issue and obtain that power?

yes, you just disconnect the battery with the extra flow and the computer will recalibrate the idle. To get that flow you ideally want to build an intake.

building an intake might just be outside my capabilities, but I'll try to disconnect the battery so the computer will recalibrate. As I understand you I should do it while the extra air flow is available?

yes, do not leave your filter box open though, having the engine ingest unfiltered air is bad for it, what you could do are cut some small holes in the bottom part of the box below where the filter sits.