Hi,
Throttle body always seems to do that. Does it on mine, especially so when turning off. As for the oil, check the one way valve in the crankcase ventilation system is ok and attached. If you have engine cover off its the white plastic connector on a short piece of hose that goes into top of throttle body. Cheap to just change it.The other end goes down back of engine to the oil trap. I clean mine out every couple of months, its always oily, yet uses very little oil. You may as well clean throttle body and the charge air pipe too for good measure. When you get it TECH2,d make a note of all codes read and pending and have all software checked and updated.
keep us posted, hope we can get you running soon.
steve