FordKawi85

Hey everyone, I'm new to this forum, but I am having a serious issue with my truck that I cannot find any help with on any forum. I have a 2005 XLT 4.6 L. Recently, my truck has been jumping/skipping coming out of/slowing to a dead stop. The tach jumps from 800 to 1300 rpms at idle and has recently started jumping from 2000 to 3000 rpms while jolting roughly when cruising at around 50 mph. My gas mileage has also severely decreased. I have cleaned the throttle body, checked the FPDM, and replaced the air filter. None of this has worked. No check engine light has displayed at all. Seems to occur mainly when engine is at full temp. Truck has 115,000 miles on it. Had the battery replaced 3 weeks ago and just started having these problems a few days ago. Any help would be appreciated because I am stumped.