Engine Performance problem
1999 Buick Century 6 cyl Front Wheel Drive Automatic 110000 miles
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99 Buick Century

Ever since I took it to San Antonio Texas and back from Amarillo Texas

After driving it for a little while it will have trouble going from a stop like it has only a fourth of the engine..

When driving on the highway it will chug and hesitate until I hit the gas then it will speed up until it changes gears then go back to its chugging.. If I try to floor it to get through an intersection or onto a highway the engine will rev up but the car will not respond.. I can be driving at a cruising speed and hit the gas to pass someone and the engine will rev up then suddenly lose all power and bog down until I let OFF the gas then it jumps like I hit the gas

Get the throttle position /mass airflow and manifold absolute pressure sensors checked out to include a fuel pressure check-