REPLACING ALL SPARK PLUGS (N42, N40, N46, N45, N52, N52K, N51)
Special tools required:
12 1 171
12 1 200.
Necessary preliminary tasks:
Switch off ignition
Remove ignition coils.
Unscrew spark plugs with special tool 12 1 171.
Installation:
Tighten down spark plugs with special tool 12 1 171a
The N54 and N52KP meet ULEV II requirements for 2007. There are not many
changes to the emission
systems on these engines. The N54 engine has 2 underbody catalysts in addition
to the "near engine" catalysts
already in use from the N52.
The N51 engine, however, is a SULEV II compliant engine which