I have a 99 A6 Avant Quattro. Started with a boost after sitting since January.. it seemed to be running fine. Took it in for an oil change & now it's barely running. It starts fine and idles OK if I keep a little pressure on the throttle, but as soon as I try to rev it, the engine stutters madly. If I take my foot off the throttle, it stalls.

Could this be a gas line issue, remedied with conditioner? There is about 1/4 tank of fuel that has been in it these 3 months. A fellow at the shop said it may be a sensor?

Any opinions greatly appreciated.

 

Might be an mass airflow sensor. Have any check engine lights on?

 

Mass air meter or huge vacuum leak

 

Thanks for your input!

The engine light did come on. Is it a coincidence that this could happen while in for an oil change? It ran fine till then.

Hoping for an easy fix as I'm putting it up for sale this weekend!

 

With the engine light coming on, even though its a bad thing, might be the answer to your previous troubles.

I fyou get it scanned, make sure you follow up.

 

Will do, thanks so much!

 

Seems the throttle position sensor needs replacing. Has anyone done this, or is it time to call the mobile mechanic?

 

The sensor is located above the gas pedal in the cab. Probably wouldn't cost very much labour, but probably an expensive part.

If you are not familiar, get someone who knows