What do I need to replace to stop rough idling, stalling ,fast idling (40mps) and surging. Already replaced throttle body sensor.
My car has 75000 miles.
My car has an automatic transmission.
A number of components or faults can cause your issues. A vacuum leak can cause your issues. Depending on the vehicle, components such as the mass airflow sensor, throttle position sensor, coolant temperature sensor, and a number of others can be the cause. Since randomly replacing parts can get expensive as most electronic components are not returnable once installed, having a certified technician, such as one from YourMechanic, diagnose the stalling/surging is the best place to start.