98 MERCURY VILLAGER 3.0 LITER CHANGED OUT KNOCK SENSOR, CAR STARTS UP AND IDLES FINE BUT WHEN YOU TRY TO GIVE IT GAS IT DIES. I CHECKED FOR VACUM LEAKS AND COULD NOT FIND ANY, CHECKED ALL HOSES COULD NOT FIND ANYTHING DISCONNECTED. IT IS SHOWING NO ENGINE CODES. DO HAVE ANY IDEAS . THANKS