GM Duramax L5P 6.6L Downpipe-Back Exhaust System (2017-2026)

Shipping

Free shipping on tuners. We aim to dispatch in-stock orders within 2 business days. Most North American orders arrive within 2–7 business days after dispatch via expedited ground. International orders typically take 5–14 business days, depending on destination and customs.

Transit time starts when your order ships, not when you place it. Weekend orders are processed the next business day. Orders shipping outside Canada may be subject to import duties and taxes, which are the customer’s responsibility on delivery. See our shipping policy for full details.

Returns

Orders cannot be cancelled after purchase. Custom tuning (files and devices), exhausts, race pipes, turbochargers, and EGR kits are final sale. We do not accept change-of-mind returns, exchanges, or refunds on these items.

Returns are only considered for items proven defective due to a manufacturing fault, and every return requires a Return Merchandise Authorization (RMA) issued in advance. Email support@dynamicdiesels.com or call 1-877-600-5667 with your order number and proof of the defect (photos, video, or a diagnostic readout). Returns sent without a valid RMA and our company-issued prepaid label — including refused deliveries or customer-arranged shipping — cannot be processed.

Faulty tuners may be submitted for a manufacturer warranty claim within 90 days of delivery; we provide a prepaid return label. If a non-fault tuner return is approved, the return-label cost and a 20–25% restocking fee apply based on condition. Damaged or incorrect exhausts, race pipes, and EGR kits will be replaced; approved EGR returns for other reasons are charged the return-label cost plus a 25% restocking fee. See our refund policy for full details.

Warranty

All tuning devices come with a 90-day manufacturer’s warranty from the date of delivery. You have a full 90 days from delivery to start a warranty claim if an issue arises. We also honor all applicable manufacturer warranties on the products we sell; coverage period and claim process vary by brand and product category.

To start a claim, email support@dynamicdiesels.com or call 1-877-600-5667 with your order number. We may ask a few questions about the device to confirm the fault, and we may request proof of communication with the manufacturer, as they are often the primary contact for device issues.

Once your claim is approved, you can choose one of the following:

• Return for replacement: Send us the faulty device, and once we receive it we’ll dispatch a replacement of the same or a similar device of equal or lesser value.
• Return for refund: Return the faulty device and we’ll refund the original payment method. Please allow 3–4 business days for the refund to appear.
• Return for gift card: Receive a gift card for the faulty device, sent to the email on file and available to use right away.

You’ll receive a Return Merchandise Authorization (RMA) number and a prepaid return label to send the faulty device back. See our refund policy for full details.