I have a 07 A4 quattro s line with 15k miles. Todaywhen I started the car, it started idling really low & the car started shaking. Once I got home, it started idling really high & then low again. Also, the check engine light went on. Going 2 dealer 2morrow, but just wondering if anyone else had this problem. I used to have an 03 a4 & the coils went out. Maybe same thing?

 

Coil pack or loose connection between pack and spark plug