21405887 Boss | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta D13 Exhaust NOx Sensor Boss - Part Number: 21405887

A precision threaded boss used in selected Volvo Penta D13 wet-exhaust, exhaust-flange and SCR muffler assemblies. It provides the correct mounting and gas-exposure position for the applicable NOx or exhaust-aftertreatment sensor.

⚙️ Key Features

• Genuine Volvo Penta exhaust-system boss

• Correct sensor thread and seating geometry

• Designed for high-temperature exhaust service

• Used in wet-exhaust and SCR-related D13 arrangements

• Provides accurate sensor positioning in the exhaust stream

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 21405887 (current catalogued reference)

OEM / Related Numbers:

• 23011585 - related SCR muffler

• 23154165 - related wet 6-inch exhaust riser

• Associated NOx sensor and sealing hardware

Aftermarket / Verified Equivalents:

• No aftermarket equivalent

🚤 Compatibility

Commonly used on:

• Volvo Penta D13 marine exhaust and aftertreatment systems

Typically suits:

• Engine models:

• D13B-N MH

• D13B-N MH (FE)

• D13C1-A MG SCR-equipped applications

• HP Range: Engine-rating dependent

• Engine Type: D13 inline-six turbocharged marine diesel

• Year Range: Exhaust-system and emissions-package dependent

🔌 Function

Provides the threaded mounting point that positions the exhaust or NOx sensor in the gas stream.

Common signs of failure:

• Damaged or stripped sensor thread

• Exhaust leakage around the boss

• Corrosion or cracking at the welded joint

• Sensor cannot be tightened or removed correctly

• Incorrect sensor reading caused by a damaged mounting seat

📦 Condition

• Genuine Volvo Penta part

• Brand new

• Supplied in original or equivalent packaging