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DEF Treatment

Emissions System

Enhances the SCR system's catalytic conversion of nitrogen oxides to reduce harmful diesel emissions and maintain regulatory compliance.

DEF treatment is a specialized additive designed for use with diesel exhaust fluid in selective catalytic reduction (SCR) equipped diesel vehicles. It enhances the SCR system's ability to convert harmful nitrogen oxides (NOx) into harmless nitrogen and water vapor, improving emissions control efficiency and helping the vehicle meet environmental regulations. This treatment is used in conjunction with regular DEF top-ups in the vehicle's DEF tank.

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Typical part cost
$8–$20🔒
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DIY difficulty
1/10

⚠️ Owners Often Notice

If the DEF Treatment is starting to fail, these are the signs owners most commonly report before it gets worse:

DEF system warning light
Reduced engine power
Failed emissions test

Related Services

Services commonly performed on or around this part.

Add DEF Treatment

No standard interval on file

Replace DEF Treatment

No standard interval on file

Flush DEF Treatment

No standard interval on file