my stock rims leak also its due to oxidzing on the inner bead of the rim what you do is take the tire offf the rim and clean it up with some sandpaper or a wire brush

It´* as said before either the vent or corrosion on the rim.
I´ve worked with tires, often older alu-wheels get´* corrosion, what you do is clean the rim. Using a steel brush. We had a machine for it. Like an electric steel brush, don´t know the word in english.
Anyway after that you apply a glue like sealent (spelling)
So get new rims if : There´* damge to the rim lika a crack or it´* bent otherwise it´* often easilly fixed.

stock chrome rims SUCK especially GM wheels, I see it on a nearly daily basis, we call it chrome cancer....once it starts to flake there is no stopping it, you can have all yer tires removed and strip them clean down to the aluminum and then spray some clear coat over them and let them dry B4 having the tires remounted on them, or you can ditch um and get some new rims. My shop ussually cleans them up as good as we can and puts on bead sealer, but its usually a temporary fix, unless you remove ALL of the chrome from the bead surface.

the car sat all sunday andi checked the air this morning before work and it was down 1 psi
do i have to buy all 4 new rims or just one for now cuz the others are fine for now.

ya gots an aluminum rim, it will most likely leak some. Aluminum is somewhat porous - they can leak thru the middle of the casting. I have sealed some by dismounting the tire, and then cleaning and painting the circumference of the rim.

Jeep Cherokee wheels leak the worst.

well it cold by you right?

when the air is cold Psi drops due to the law of density

Same thing happend to me over the summer... it was a small hair thin crack on the inner side of the rim, had to have a aluminum welder guy fix it.....