When your equipment runs on a Perkins engine, ensuring your emissions system works properly isn’t optional—it’s essential. The Perkins DEF Head Unit (OEM T434814) is a key component in the Diesel Exhaust Fluid (DEF) circuit, responsible for accurate sensor feedback and proper dosing. If it’s failing or not up to spec, expect warning lights, emission faults, or derates that can cost downtime and money.
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Monitors DEF fluid level, temperature, and concentration (urea content) and sends accurate data to the engine control module
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Controls the precise dosing of DEF into the exhaust stream so the Selective Catalytic Reduction (SCR) system can reduce NOx emissions properly
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Matches OEM T434814 specifications, ensuring proper fit, compatibility, and reliability with Perkins-powered equipment
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Helps prevent fault codes, emission system warnings, and engine derates caused by poor or erratic sensor readings
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Built to withstand challenging conditions: vibration, thermal swings, and exposure to DEF fluid chemistry
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Replacement is made simpler with OEM matching, reducing repair time and getting your machine back to work
If you’re seeing DEF-related errors or experiencing emissions warnings on your Perkins engine, this T434814 DEF Head Unit might be exactly what your system needs. A solid, properly calibrated unit restores feedback accuracy, keeps the SCR system functioning, and helps avoid surprise downtime.









