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.

Items Eligible for Return

These items can be returned within 30 days of the purchase date if they are unopened, unused, and in their original packaging:

• Tuning devices: an unopened, unused Mini Maxx V1/V2 or a blank EFI Live device.
• Cables and device accessories: an unopened, unused switch, bypass cable, universal pyrometer, or docking station.

Final Sale

The following items are final sale and cannot be returned:

• Custom tuning: additional tune files purchased separately, and custom tuning purchased with a device.
• Exhausts and race pipes: including downpipes purchased separately from an exhaust or race pipe.
• EGR kits.

Manufacturer Warranty

Every item we sell includes a 90-day manufacturer warranty. An item returned for a manufacturer defect can be refunded in full, exchanged, or replaced with a similar item of equal or lesser value.

Eligible items returned for any other reason follow the same options — a full refund, an exchange, or a replacement of equal or lesser value — as long as the item meets the requirements above.

Return Process

Every return must be approved before it is sent back. Email support@dynamicdiesels.com or call 1-877-600-5667 and we’ll issue a valid Return Merchandise Authorization (RMA) number and a prepaid return label.

Do not send anything back without an approved RMA and the return label we provide. Returns sent without both will not be accepted or processed. 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.