In modern diesel engines, emissions control isn’t optional—it’s a required system. A critical but often overlooked part of that system is the DEF (Diesel Exhaust Fluid) head unit. For CAT platforms like the C4.4, the OEM 5913427 DEF head unit is foundational to keeping your aftertreatment working reliably. When this component fails, your engine can throw error codes, derate, or exhibit other emissions-related issues.
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Monitors DEF fluid level, temperature, and urea concentration, giving the engine’s ECU accurate feedback
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Ensures precise dosing of DEF into the exhaust stream so the SCR (Selective Catalytic Reduction) system can reduce NOx emissions correctly
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Built to OEM 5913427 specifications for plug-and-play fit and calibration with CAT systems
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Helps prevent fault codes, emission warnings, and engine derates caused by sensor drift or failure
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Constructed to endure vibration, thermal cycling, and exposure to DEF chemistry
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Designed for replacement with minimal fuss, helping you get back in operation faster
Don’t let a degraded DEF head be the weak link in your emissions chain. Installing a quality OEM 5913427 DEF Head Unit for CAT C4.4 restores sensor fidelity, protects the SCR system, and keeps your engine running clean and compliant—including when operating under stress or in harsh conditions.