MY CHEVERLOT EQUINOX STOP ACCELERATING LAST NIGHT. IT STILL TURNS ON. WHEN IN PARK AND YOU PRESS THE GAS IT REVS UP. WHEN IT IS IN REV OR DRIVE AND YOU PRESS ON THE GAS IT MAKES A CHOKING NOISE AND EVENTUALLY A GRINDING NOISE AS WELL. CAN YOU LEAD ME DOWN THE RIGHT PATH. IS THIS A COSTLY REPAIR