I got a P0300, 0301, 0302, 0303, 0171, 0131 the first 4 are miss fires the 0171 fuel trim,bank1 system too lean and 0131 O2 sensor circ.,bank1 sensor low voltage I have changed the spark plugs, switch the coils from right to left and left to right. I do have a Bentley Audi A6 service manual from 1998 to 2004 btw i got a 2003 Audi A6 Quattro AWD 2.7t its got 150psi compression or higher in all cylinders and it's got a manifold leaks and when I changed the spark plugs the driver side plugs were white and passengers side was black as f!!!