I have had my A8 for one year. All has been until my engine light came on and started blinking. The car just quit running. It will start but has a miss. My mechanic said that the passenger side of the motor is not running. The timing belt was replaced 20K ago. My mechanic has not figured this out yet. Can you help please?

 

VCDS scan is the only way to know for sure, but my guess is cam position sensor.

 

try the ignition control modules. there is one for each side of the engine. located just behind the windshield washer fluid reservoir, on top of the wheel well. there are 4 pins on one side of the module and 5 on the other side. use and ohm meter between the center pin on the 5 pin side and each of the 4 pins on the other side. you should find one of the 4 pins tests different than the rest. do this check on each of the 2 modules.