I've got a 2001 Audi tt quattro. At first the check engine light was on and after sitting over night when I would go to start it in the morning it would sputter like it wanted to stall and then throughout day it is fine. I took it to dealership, they put a new air massive sensor, check engine light came off but yet it still starts the same way in the morning. The sputtering and hesitation is still there.

 

lots of possibilitys, small tiny boost leak, old fuel filter. give your car some time to adapt to the new mass sensor and it may go away on its own.

 

Thx for your input.

 

Clean the fuel and air filter. Hope you are using a good hi-octane fuel.

 

My 01 tt quattro is having an issue. I was sitting at red light and as I drove through and shifted into 2nd... the car lost some power, heard a beep as red oil light came on then it turned off. I pulled over... turned car off and then it wouldn't start. I towed it to house.. it sat overnight and started in morning then wouldn't restart. The oil light hasn't come back on.. just came on that first time and that's it. I also checked oil level n it was about a quart in a half low and dip stick sleeve was all shattered so I replaced that. What could be wrong??

 

timing belt? maybe?
as you're looking in the engine bay, left side, there will be a black cover for the timing belt, prop it open and visually see if there are any teeth missing on the belt.
hope this helps

 

I had a similar problem to this, except my EPC light came on with the check engine light. After a year and a half, my mechanic has found the complete problem. It was electrical and the electrical harness was fried and had to be replaced. Check to see if that may be the problem.

Good luck!

 

Timing belt is fine. Could it be oil pump or sensor? Car still starts after sitting overnight. When it does start there still isn't any warning lights on. Then when I turn off and go to restart it just turns over. I will check electrical harness. Do you know where this is located?

 

strange how someone would take it to the dealer before they even checked the CEL code.
Especially when you can do that for free at places like AutoZone.

 

What I am talking about now has nothing to do with what you are saying about taking it to dealership. I did it because I chose to and its already taking care of. My issue now is something totally different. So keep your smart remarks to yourself