I have a jetta 2001, it will not accelerate at all or rev up. The EPC light is on. We've replaced the throttle body and 02 sensor because thats what came up on the code reader but still nothing.

are you using a base obd2 scanner or rosstech software? OBD2 readers only get surface answers and don't often lead to the right part causing the issue. It sounds to me like the car is in limp mode if it starts runs and moves. Try cleaning all the sensors in the MAF and check all the crank case breather hoses. They are located plugged into the head and go back to the throttle body. Check all the vacuum lines and check for spark and fuel. if all these are good its probably just a sensor. If you haven't already take it to a VW specialist and have them scan it. often enough they dun charge anything for a single scan. will help trouble shoot the issues.