The left head on the 3.6
The left head on the 3.6 pentastar motor had the cooling passages drilled too small, cylinder 2,4 and 6 misfires are common due to the exhaust valves burning. It is a fairly simple fix and we can usually turn them around in a day or two. This issue is also full line up wide, I personally have seen this misfire on caravan/town and country platform, wrangler, grand Cherokee/ dodge durango platform, and 200/avenger platform.