Probably the piece of junk float switch in the fuel module. Mine went bad in my 2012 and it would sputter and almost die out at different stages, sometimes idle, sometimes throttled down. The float switch appears to be a $2 cheap part but they'll charge you about $60 online. It completely solved my issue. It will take about 1/2 hour to replace and is a pretty simple fix. Hope that's the issue because it pretty simple fix.