NAMZ Custom Cycle O2 Sensor Extentions & Bung Reducers - 18mm TO 12mm Pair — Harley-Davidson (2012-2026)

NAMZ Custom Cycle O2 sensor extensions with 18mm-to-12mm bung reducers let you fit older-style exhaust headers onto newer Harley models where sensor bosses have moved or changed size. This pair includes pre-installed terminals without connectors, ready to splice into your existing wiring harness.

Features

• 18mm to 12mm bung reducer pair
• Pre-installed terminals (connectors not included)
• 6-inch extension length
• Allows 2009 headers to fit 2010-up models

Specifications

• Brand: NAMZ Custom Cycle
• Manufacturer Part #: NBR-01
• UPC: 810088715372
• Length: 6 in
• Width: 4 in
• Height: 0.75 in
• Weight: 0.3 lbs

Fitment

Fits 2012 and newer FXST and Dyna models. Allows fitment of 2009-style header pipes that would otherwise be incompatible with 2010-up sensor locations and boss sizes.

Frequently Asked Questions

Will this let me use my 2009 headers on a 2010+ Harley?

Yes — the 6-inch extensions reach the relocated sensors on 2010-up models, and the bung reducers adapt the different boss sizes between years.

Do the connectors come installed?

Terminals are pre-installed, but connectors are not included. You will need to splice them into your bike's wiring harness or source compatible female connectors separately.

What size reducers are included?

This kit includes 18mm-to-12mm bung reducers. Verify your header bung and sensor hole sizes before ordering.

Will these work on models other than Dyna and FXST?

This kit is designed for 2012+ FXST and Dyna models. Other cruiser models may require different extension lengths or reducer sizes — contact NAMZ to confirm fitment.