2008 Chevy Impala LT 3.5L engine, RPMs randomly cut, car won't go 40+
My boyfriend's car sometimes randomly acts up! The car will jitter and then has a hard time getting up to 40/45, and will not go past 45. The car runs fine when it gets up to speed, but in order for him to be able to drive the car when this occurs, he must manually put the car into 2nd gear. After shutting off the car for a few minuets and restarting the engine seems to fix the issue, however shutting off the car and turning it on doesn't always fix the problem.