Crank sensor

My car suddenly stop running at a red light. The engine would turn over but wouldn’t start. Towed to machanic. Diagnosis- faulty crank sensor. $450.00 later, sensor replaced. Now it runs but seems to have reduced horsepower. Idles smoothly, but strains, loudly complains, on harder acceleration like entering the interstate on an incline or going up steep hills in NC. Took it back to machanic but seems to have no clue. Help!

Did your check engine light ever come on or (more importantly) flash before this happened?
Is the check engine light on now?

What kind of car? Some cars have the crank angle sensor built into the distributor, which fine tunes the timing. If yours does, it’s possible that the dizzy is rotated just a little beyond where it should be, and the timing is messed up.