Harddrive O2 Sensor Adapter - Reducers 18mm TO 12mm PR — Harley-Davidson Electra Glide, Electra Glide Classic, Electra Glide Ultra Classic (1955-2026)

Harddrive O2 sensor adapter that reduces an 18mm O2 sensor bung to 12mm, allowing you to run an O2 sensor in a performance exhaust that uses a smaller bung location. Essential when upgrading to an aftermarket exhaust on Touring models or pairing earlier exhausts with 18mm bungs onto later bikes.

Features

• Reduces 18mm bung to 12mm
• Fits Touring models with performance exhausts
• Allows earlier exhausts on later model bikes
• Direct bolt-in installation

Specifications

• Brand: Harddrive
• Manufacturer Part #: 52-830
• UPC: 191361115363
• Length: 6.29 in
• Width: 3.74 in
• Height: 0.78 in
• Weight: 0.022 lbs
• Country of Origin: China (Taiwan)

Fitment

Fits V-twin motorcycles, particularly Harley-Davidson and Indian Touring models using performance exhausts or mixing exhaust generations.

Frequently Asked Questions

What size bung does this adapter fit and reduce to?

Fits an 18mm O2 sensor bung and reduces it to 12mm for compatibility with modern O2 sensors.

Can I use this to run an older exhaust on a newer bike?

Yes — if you have an older exhaust with an 18mm bung and want to run it on a later model bike with a 12mm sensor, this adapter bridges the difference.

Do I need a tuner if I install this?

The O2 sensor adapter itself does not require a tuner — it simply allows your existing sensor to work in a different bung size. Consult your exhaust and ECU setup for any related tuning needs.

What's the installation process?

Screw the adapter into the 18mm bung and then install your O2 sensor into the 12mm end. No special tools required.

Is this the same as buying a new O2 sensor?

No — this adapter allows you to reuse an existing O2 sensor by changing the bung size. You keep your current sensor.