P1136 Volkswagen -

Question

PASSAT 2003 1.8L CHECK ENGINE LIGHT ON,SCAN THE SYSTEM,2 FAULT DETECTED P1136,P0011........BANK 1 MIXTURE ADAPTATION SYSTEM TOO LEAN,INTERMITTENT,2nd FAULT A CAMSHAFT POSITION/BANK 1 ,TIMING OVER-ADVANCED OR SYSTEM PERFORMANCE
WHAT IS POSSIBLE PROBLEM AND SOLUTION