Knock Sensor Adapter Stud for Bosch 2 Wire Knock Sensor – (12X13)

Knock Sensor Adapter Stud

Most Honda B, D, K, and H-series engines use a single-wire knock sensor threaded directly into the block — a design that works fine with the factory ECU but isn’t compatible with standalone systems like Haltech, which require a two-wire Bosch-style flat knock sensor. This OEM Honda bolt solves that problem cleanly.

The part threads into the factory M12 knock sensor boss in the block, then presents an M8 stud that mounts a standard two-wire Bosch donut-style knock sensor using a 12 mm flange nut. No drilling, no adapters, no fabrication. The sensor sits flush against the block surface the same way Honda intended, which matters for accurate knock detection — sensor clamping load and contact with the block directly affect signal quality.

A straightforward solution for anyone building a standalone-tuned Honda that needs proper knock sensing without chasing Toyota stud workarounds or custom machining.

Base thread (into block): M12 × 1.25
Base length: 13 mm
Stud thread (sensor mount): M8 × 1.25
Stud length: 30 mm
Requires: 12 mm flange nut (not included)

Factory Part Number: 11109-R1A-A00