Engine dies when shift to any gear.
 

Hello everyone! I have a 2005 Freestar. When I shift transmission to any driving gear the engine immediately dies. It works okay at 'P' and 'N' only. When i try after 10-15 min of idling it doesn't die right away but vibrates terribly. I replaced the idle control motor but it didn’t help. I don't think it's transmission because it worked fine before. Now I am thinking that it might be a neutral safety switch causing this. I would very much appreciate your thoughts on this.

neutral safety switch is used to prevent cranking of the engine when its in gear. it effect the starting circuit only...no effect when the key is in run.

any codes for torque convertor clutch stuck on?
-does it have less power when you accellerate from a stop?

if the tcc doesn't release, the trans mission remains connected to the engine and causes the stall....similar to stopping a vehicle with a standard transmission in gear without depressing the clutch

Thanks Primem for the reply. I have not done diagnostics. It happened suddenly when I was driving home it started vibrating at a stop. Next day it wouldn't drive. But now I am pretty sure it's the mass air flow sensor causing a problem. Yesterday I cleaned it with air a bit and it got better. Engine doesn't shut down when in gear anymore though there's still a bad vibration. Gonna buy a special sensor cleaner. Will let you know what happens.

Well it was not a MAF sensor causing the problem. Will let you know when a problem is found.