2002 Sprinter has a rough idle when cold, smoothes out to a small vibration when warm.also replaced high pressure pump and now have a loud diesel knock around 1500rpm when going from idle.it only happens when it drops to idle and back up. At idle i have a low rattle which sounds like its coming from the fuel rail or #5. the following codes are present p1354-32 cam sensor, p1187-01 fuel pressure switch, p2006-01 low side fuel pressure and p1188-08 fuel shut down. rough idle was present before pump replacement. have clear codes and waiting to check again. any help as what to check would be great. total newbie