I feel for ya. I have had this problem since my 2011 Crew was brand new. I have had in looked at by "3" different dealerships a total of 16 times, along with transmission issues and wheel shake. The first time they admitted it was a problem, and it was due to water in the gas (free fill up they gave me when I purchased) after 2 tanks of fresh gas, it persisted. Now they said it was completely normal. The engine was trying get the idle as low as possible to conserve fuel. There was no misfire, even though Chrysler had a huge issue with misfires due to bad heads, and were replacing about 17,000 of them free of charge. They told me each time that they could not do ANYTHING without the engine throwing a code, or a MIL. I finally got Chrysler to give me a 100,000 mile warrantee in leau of me pushing to Lemon Law it.