Frequently Asked Questions About Kenworth T660 DPF & Mufflers

What years does the Kenworth T660 DPF system fit, and are there different versions I need to know about?

The Kenworth T660 was produced from 2008 to 2016, and DPF systems vary significantly based on your engine type and EPA compliance year. Pre-2010 models typically use different DPF configurations than 2010-2016 models due to EPA regulation changes. Always verify your specific engine model (Cummins ISX, PACCAR MX, or Caterpillar) and serial number before ordering, as each requires different mounting brackets and inlet/outlet sizes. The easiest way to ensure compatibility is to check your existing DPF part number or contact us with your VIN.

How difficult is it to install a replacement DPF or muffler on my T660, and what tools will I need?

Installation typically takes 2-4 hours depending on your experience level. You'll need basic hand tools, including socket sets (typically 13mm-19mm), wrenches, and potentially a sawzall for removing corroded clamps. The main challenges include dealing with seized bolts due to heat cycling and ensuring proper alignment with existing exhaust components. Many customers report needing new gaskets and clamps, which we recommend ordering with your DPF or muffler. Professional installation may be worth considering if you lack a lift or proper exhaust hangers.

What's the difference between OEM and aftermarket DPF filters for my T660, and which should I choose?

OEM DPF filters typically cost 40-60% more than quality aftermarket options but offer exact fit guarantee and original specifications. Aftermarket DPFs from reputable manufacturers like Skyline, Redline, and Dinex provide comparable performance at lower cost, often with better warranty terms. The main differences include substrate material (cordierite vs. silicon carbide) and cell density. For trucks under warranty, stick with OEM. For older T660s, aftermarket options offer excellent value. Always ensure any aftermarket DPF is EPA compliant and includes proper documentation.

How often should I clean or replace my T660's DPF, and what are the warning signs of failure?

DPF cleaning intervals typically range from 150,000 to 250,000 miles depending on duty cycle, idle time, and maintenance habits. Warning signs include frequent regeneration requests, reduced fuel economy (2+ MPG drop), check engine lights with codes P2002 or P2459, and excessive black smoke. Face plugging (visible soot at inlet) indicates immediate cleaning need. Complete replacement is usually necessary after 2-3 cleanings or around 500,000-750,000 miles. Running quality diesel fuel, maintaining proper engine health, and avoiding excessive idling significantly extends DPF life.

Can I upgrade to a different muffler style on my T660, and what options provide the best sound without being too loud?

Yes, the T660's modular exhaust system allows various muffler upgrades. Popular options include straight-through designs for moderate sound increase and improved flow, or chambered mufflers for deeper tone without excessive volume. Stack-exit configurations require different mufflers than frame-exit systems. Most drivers prefer 4-inch or 5-inch diameter mufflers in the 36-44 inch length range for optimal sound balance. Avoid removing mufflers entirely, as this creates drone at highway speeds and may violate local noise ordinances. Jones Exhaust, Donaldson, and Grand Rock offer T660-specific options with good fitment.