Hello, I have a 2002 Audi A4 Quattro 3.0L V6 Avant. Every once in a while my car will stall, it takes between 3-4 cranks to start back up and runs with the EPC light on. There really isn't that much power loss but when stopped I feel like the car wants to "lurch" forward (have to hold the brake harder). The car will drive at regular speeds in while EPC light is on. I can turn the car off and back on and it will run normal again for sometimes very long periods of time (100 miles). The problem is intermittent so if it were a true mechanical problem I am assuming the car would run like crap all the time. A while back my splash guard underneath the engine got broken so I was wondering that water could have possibly caused some issues with wiring/sensors. I read somewhere that this might be the crank shaft position sensor because the speedometer works fine. Would replacing the crank shaft position sensor possibly fix this issue?

 

I have a 2001 Audi A6 Avant and recently my car stalled at a red light. I tightened the terminals and it started right up. This has happened before, a few weeks ago. Could there be a bad connection?

 

If the check engine light is on, pull the OBD codes and report back with what they are. There will be a code telling exactly what sensors is reporting issues. Even if it's running fine at the moment, the code will be store in the ECU until cleared.