car has 150k just put new timing belt ,water pump,termo, belts ,tires, breaks, syn oil , was running good , now for the last month or so it been geting really bad gas mileage (like 10 mph ) i changed the pvc valve ,helped a lil like maybe 11mph get like 200 miles to the tank something is wrong !!!!!!!

 

o also changed fuel filter , trans fluid flush , air filter , plugs , basic tune up stuff .,\cleaned the throttle body , dont know what else to do , today i tryed seafoam in the crankcase , an through the valcum (spelling )