How to Reduce Emissions in Your Diesel Truck and Stay Compliant

Did you know that although diesel trucks are crucial to many industries, they also contribute significantly to air pollution? Regulations continue to tighten, making it critical for truck owners and fleet operators to find ways to reduce emissions while staying compliant. Fortunately, advancements in technology and simple maintenance practices can go a long way in keeping your truck eco-friendly and legally on the road.

Understanding Diesel Emissions and Compliance

Diesel engines produce several harmful pollutants, including nitrogen oxides (NOx), particulate matter (PM), and carbon monoxide (CO). To combat these emissions, the EPA and California Air Resources Board (CARB) enforce strict emissions standards, especially in areas like Brea, CA. Compliance isn’t just about avoiding fines—it’s also about reducing environmental impact and improving engine efficiency.

1. Keep Your Diesel Particulate Filter (DPF) Clean

The DPF is designed to trap soot and other particulate matter before they leave the exhaust. Over time, the filter gets clogged, reducing engine efficiency and increasing emissions.

How to maintain your DPF:

• Perform regular regenerations to burn off accumulated soot.
• If regenerations fail, consider a forced regen with a diagnostic tool.
• Avoid excessive idling, which clogs the filter faster.
• Get a professional DPF cleaning if needed.

A clean DPF ensures your truck operates efficiently and remains compliant with emissions regulations.

2. Use High-Quality Diesel Exhaust Fluid (DEF)

Selective Catalytic Reduction (SCR) systems rely on DEF to break down NOx emissions into nitrogen and water vapor. Using low-quality or contaminated DEF can lead to system malfunctions, increased emissions, and costly repairs.

Best practices for DEF use:

• Always use API-certified DEF.
• Store DEF properly to prevent contamination.
• Never let your DEF tank run dry—it can trigger a derate mode.

Regularly checking your DEF levels ensures your SCR system works efficiently, keeping emissions within legal limits.

3. Keep Your EGR System Functioning Properly

The Exhaust Gas Recirculation (EGR) system lowers combustion temperatures, reducing NOx emissions. However, carbon buildup in the EGR valve and cooler can lead to malfunctions.

How to maintain your EGR system:

• Clean or replace EGR valves as needed.
• Inspect and clean the EGR cooler to prevent blockages.
• Use high-quality diesel fuel to reduce carbon buildup.

A properly working EGR system prevents excessive emissions and keeps your truck running smoothly.

4. Upgrade to Low-Emission Engine Tuning

Many modern diesel trucks allow for ECM tuning to optimize fuel injection, air-to-fuel ratios, and exhaust after-treatment processes. Tuning your truck for lower emissions can help improve compliance and fuel efficiency.

What to consider when tuning:

• Work with a certified tuning professional to avoid illegal modifications.
• Ensure tuning adjustments do not violate CARB or EPA regulations.
• Choose tunes that balance performance and emissions reduction.

Proper tuning can significantly lower emissions while maintaining your truck’s power and efficiency.

5. Use Ultra-Low Sulfur Diesel (ULSD)

ULSD fuel contains 97% less sulfur than traditional diesel, reducing sulfur dioxide emissions and extending the life of your DPF, EGR, and SCR systems.

Tips for using ULSD effectively:

• Ensure your truck is compatible with ULSD.
• Always buy fuel from reputable stations to avoid contamination.
• Consider adding diesel fuel additives to improve lubrication and performance.

Using ULSD is not only a regulatory requirement but also essential for protecting your truck’s emissions system.

6. Reduce Idling Time

Excessive idling contributes to higher emissions, fuel waste, and DPF clogging. Many states and cities have strict idling laws, including California, which limits idling to 5 minutes in most cases.

Ways to reduce idling:

• Use auxiliary power units (APUs) or battery-powered HVAC systems.
• Shut off the engine during long waits instead of idling.
• Plan routes efficiently to minimize downtime.

Cutting down on idling improves fuel economy and helps your truck remain emissions-compliant.

7. Regularly Inspect and Maintain Your Exhaust System

Leaks or damage in your exhaust system can cause increased emissions and potential compliance issues.

How to maintain your exhaust system:

• Check for cracks, leaks, or rust in exhaust pipes and mufflers.
• Ensure the catalytic converter is functioning properly.
• Replace worn-out components before they cause bigger problems.

A well-maintained exhaust system ensures all after-treatment devices work as intended to reduce emissions.

8. Stay on Top of Preventive Maintenance

Routine maintenance is key to keeping emissions low. A well-maintained engine runs more efficiently and produces fewer pollutants.

Key maintenance tasks:

• Change engine oil and air filters regularly.
• Inspect fuel injectors for leaks or inefficiency.
• Perform BIT inspections (if applicable) to ensure compliance with safety and emissions laws.

By staying proactive, you avoid expensive repairs and keep your truck within legal emissions limits.

Final Thoughts

Reducing diesel emissions isn’t just about following the law—it’s about keeping your truck running efficiently, reducing costs, and protecting the environment. From keeping your DPF clean to using high-quality DEF and ULSD, small steps can lead to significant improvements.

Need help staying compliant? A Plus Mobile Maintenance in Brea, CA specializes in diesel emissions systems and maintenance. Contact us today to ensure your truck meets emissions regulations and stays road-ready!