My throttle isn't sticking but after replacing my clutch with an aftermarket one if I put it in neutral and or hold the press the clutch pedal all the way down and rev the engine, at around 4000rpm it will start lurching forward. It recently went out again and I am sure it is either the clutch slave or the throw out bearing. I just replaced the clutch master cylinder and it wasnt that so it has to be one of the other two things. Good luck and you might take it back and have whoever did it check it out again.