My friend has a Dodge Ram truck, like a 93 or 94, not sure on exact year. When you apply the brakes while its in gear, it wants to kill the engine, and sometimes it does... its especially bad while in reverse.

What causes this? And how hard would it be to fix? Any info would help a lot, thanks!

 

Check for a vacuum leak,check at the booster when brakes are applied.

 

Sounds Like the Idle air control is sticking. If you find this to be the problem make sure you get the revised one from dodge.