2011 Dodge Grand Caravan stability control problems

When starting, the engine occasionally makes a rattling noise and check engine light comes on. I took it to the dealer and after stating that no codes were captured, they cleared the code. The check engine light came on again so I took it back and they replaced the cam position sensor, which they said would fix it. It didn't and the check engine light continues to come on with a rattling at the start which now occurs more frequently.

Van will shut off while driving at slow speed, normally when slowing down to turn, which is very dangerous as you have to coast across the road with no power. No check engine lights or error codes of any kind. This has happened several times almost causing accidents. The engine does run abnormally and performs well at highway speeds. When the problem happens it is just as if you turned off the ignition, but the radio and dash lights still work. The van will restart normally and drive.