Hi i am new to the audi family. I just purchased a 2000 A4 1.8t quattro 5 speed and on the way home the CEL came on and later it started stuttering at higher speeds (60 mph and above). So i hooked it up to the scanner and it was error code P0411 secondary air injector incorrect flow. I have read a bit about it but like i said i am new to audi. Im not even sure where to start with it. I know it is located under the air filter box but dont even know what im lookin for. How serious is this problem any help would be great. Thanks