Well, the Sable finally left me sit at Boscov's yesterday. I had it jumped then picked up a battery. The CEL isn't on at this time so I believe that the battery caused the P1633 code. The stumble is still there though...

 

I'm glad the battery fixed that problem. Have you cleaned your MAF (Mass Air Flow) sensor? They can cause your engine to run rough. Take off your air intake snorkel and spray the thin wire of the MAF sensor with electric cleaner. It's very fragile, so don't attempt to physically clean it with a rag or anything.

 

I have not tried to clean the MAF. I will do that . I cleaned out the IAC before though. I'll let you know...