Frequently Asked Questions About Peterbilt 330/335/337 DPF & Mufflers

Will these DPF systems and mufflers fit my specific Peterbilt model year?

Our DPF systems and mufflers are designed for Peterbilt 330, 335, and 337 models typically ranging from 2008-2015, which coincides with EPA emission requirements. However, compatibility can vary based on your specific engine configuration (Paccar PX-6, PX-7, or Cummins ISB). Before ordering, check your VIN or existing part numbers, as some mid-year production changes may affect fitment. We recommend calling our technical support team with your truck's serial number for exact verification.

How difficult is the installation process, and what tools will I need?

Installation typically takes 2-4 hours for experienced mechanics. You'll need standard shop tools including impact wrenches, jack stands, and potentially a torch for removing rusted clamps. The main challenges include accessing tight mounting points near the frame rails and properly aligning the exhaust hangers. Many customers report needing to slightly modify or adjust hangers for optimal fit. Professional installation is recommended if you're not comfortable working with exhaust systems, as improper installation can trigger fault codes.

What's the difference between OEM and aftermarket options in terms of quality and longevity?

OEM DPF units typically last 200,000-400,000 miles with proper maintenance, while quality aftermarket options can achieve similar lifespans at 30-50% less cost. The key differences are in the substrate material and precious metal coating density. Aftermarket units may require more frequent cleaning intervals (every 150,000 miles vs. 250,000 for OEM). Look for EPA-certified aftermarket options that meet or exceed OEM specifications to ensure compliance and avoid check engine lights.

Can I replace just the DPF filter or muffler separately, or do I need the complete system?

You can replace components individually in most cases. If your DPF filter is clogged but the housing and sensors are intact, a filter-only replacement can save significant money. However, if you're experiencing frequent regeneration issues or have damaged temperature sensors, a complete system replacement may be more cost-effective long-term. Mufflers can almost always be replaced independently unless there's damage to the connecting pipes or mounting brackets.

What are the warning signs that my DPF or muffler needs replacement?

Common indicators include frequent or incomplete regeneration cycles, reduced fuel economy (10% or more decrease), excessive black smoke during acceleration, and dashboard warning lights for exhaust temperature or backpressure. Physical signs include visible cracks in the DPF housing, excessive rust on muffler shells, or rattling sounds indicating internal baffle failure. If you notice any combination of these symptoms, have your exhaust system inspected immediately to prevent more costly engine damage.