temp light and stalling????

Hello all,
I have a 1999 Jetta Wolfsberg 2.0 4 banger.
The water pump bearing recently went out so I replaced it. I noticed the odometer was at 93,000 so I changed the timing belt at the same time.

The water pump went in good and so did the belt.

Started right up first try and ran fine.

Filled with water/coolant and let run. The Temperature light began to flash but the temp was running cool / normal. It eventually went away, but after 2 days it came back on and flashes. Water level is great and so is temperature???

Any ideas???

Next Problem: After battery strangely died over night. I rechaged it. Now it idles but when I try to drive off the engine completly dies with any load on it??? And the idle drops low for a moment..
Does anyone know what this problem could be? I read a post about the belt jumping a tooth but all the marks are lined up.

Any help would be greatly appreciated.
Thank you.

Well I plugged in the scan tool and it is telling me the MAS is bad. Has anyone else had their MAS go bad?