P0020 / 17944 S4 B6
 

I have a 2004 Audi S4 Cabriolet 4.2L B6 and have a DTC P0020 on one code reader and 17944 on the other one. How should I troubleshoot this and what are the common problems? The engine starts fine and runs fine except when in heavy stop and go traffic when it starts to get hot and starts throwing multiple Cylinder misfire codes. Clearing the DTC removes all the codes but the P0020 /17944 comes back as soon as the engine is started. Is this a common problem? The engine has less than 75K miles on it.

After a lot of research it appears that one possibility is that the camshaft oil control valve for bank 2 intake camshaft may have become disconnected or fouled or failed. Where would this item be located and what is a good part number for replacement? Comments and suggestions are appreciated.