Used in custom applications to reduce exhaust sensor thread from 18mm x 1.50 to 12mm x 1.25 so late H-D models; equipped with 12mm O2 sensors; can be used with earlier 18mm sensor style exhaust systems. Note: For 10-16 Touring models an extra extension cable is required; which is available as 578303 bung set & cable extension kit.
NAMZ, 18mm to 12mm exhaust sensor bung reducer set
€27.00
12-17 Softail; Dyna (with pre-2012 exhaust) (NU); Custom applications to reduce 18mm O2 sensor holes to 12mm