My car starts perfectly but dies when i try to take off or even just after revving it on 2001 Audi A4

My car was running perfectly yesterday and this morning when i turned it on it started fine, it was running fine but when i tried to take off it died. Every time it will start perfectly but if i even rev the car it will die after, i am wondering if anyone knows whats wrong?? thanks

Asked by for the 2001 Audi A4
have your fuel pump tested for pressure to make sure its correct and Id start from there
i went down and asked my mechanic might it be that but he said it probably wouldn't be that but it might be the air sensor?