Sharon

Hello. I am at my eits end with this car right now, but I'm hopeful someone here can help. I have a 2016 fusion 2.0 ecoboost. I have 69000 miles on it. I recently replaced the timing cover gasket, turbo, and axle seal for leaks. I got my car back and the idle is bad. It drives fine from what I can tell, but when I come to a complete stop after 5-10 secs the idle jumps between 500-1000. If I sit an excessive amount of time it will stall. I just also noticed that my mpg is terrible. I drove 34 miles and I went from 233 til empty to 185. I have no codes or lights. I replaced the throttle body and the spark plugs with no difference after. If we rest the Kam it runs perfect for about 10 minutes then reverts back to the terrible idle. Dealer is no help and none of the techs that have checked it can find the problem. Any ideas are greatly appreciated. Thanx for reading.