What this means is your getting to much air flow in mixture.
The pcm/ecm is adding fuel to compensate .
02,S were doing their job..so was not 02 problem.
For it to be rich on one bank only ..i,am thinking a vacuum leak ...or bad injector.
Will need to do a fuel pressure check ..see if pressure stays up.
Have to watch it for awhile see if pressure drops ..with key on.
A dirty maf may cause this....make sure all in maf air stream is closed up tight.
Any air leaks will cause pcm to add more fuel.
On the stall ..do a relearn of the iacv..will find you a good things to check list .
Have one bookmarked somewhere.