MagnaFlow 51966 is an OEM Grade, Federal and EPA compliant direct-fit catalytic converter for the 4.2L V8, engineered to bolt into the factory location and clear OBDII emissions codes. The spun body uses 16-gauge 409 stainless steel with mandrel-bent 2.5 inch tubing, a precision stamped collector for smooth exhaust flow, and Torca AccuSeal clamps that apply even 360 degree clamping force. A single laser fusion weld and 308 stainless MIG welds seal the housing, while the compact, low mass design improves thermal efficiency. Included hardware lets you install it with no cutting or welding, and it interchanges with OE parts 4E0 254 550 TX and 4E0 254 551 X.
Specifications
| Type | Direct-fit catalytic converter (spun body) |
| Grade | OEM Grade |
| Emissions Compliance | Federal/EPA compliant (not legal in California) |
| Body Material | 16-gauge 409 stainless steel |
| Pipe Diameter | 2.5 in |
| Clamps | Torca AccuSeal |
| Included Hardware | Gaskets and mounting hardware |
| OEM Interchange | 4E0 254 550 TX, 4E0 254 551 X |
| Quantity | 1 |
| Part Number | 51966 |
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2005-2006 | Audi | A8 Quattro | Base |
| 2004-2006 | Audi | A8 Quattro | L |
Shipping
- Orders placed before 3 PM ET typically ship the same business day. Larger items ship within 1 to 3 business days.
- Standard, expedited, and overnight options at checkout.
- Oversized items ship by freight and take longer.
- Special order items follow a lead time we confirm with you individually before the order is committed.
- Backordered items ship as soon as stock lands. Lead times are manufacturer estimates and can change. Contact us for current ETAs.
- Need to cancel? Email us right away. Cancellations are not guaranteed once an order is in process. In-stock orders cancel free before they ship; a 6% fee applies only to confirmed backorders and special orders.
- International orders: prices do not include VAT, duties, or import fees. Your country charges these at import and they are the buyer’s responsibility.
Returns
- 30 days from delivery to request and ship back a return on new, uninstalled items in original packaging with all hardware.
- Standard returns: 8% restocking fee on the item price before tax and shipping. Shipping is not refunded in either direction. All waived if the item is defective or we made the error.
- Fitment guaranteed: select your vehicle above, or confirm fitment with us in writing before you order. If the part shows as a fit and it is wrong, the return is on us, even after installation. Otherwise, installed or used parts cannot be returned.
- Final sale: special orders, coilovers, electronics, engine internals, turbochargers, superchargers and turbo kits, unless defective or we sent the wrong item.
- Product images may be representative. The SKU and specifications in the listing are what ships.
- Email us for return authorization before shipping anything back.
Full details: Shipping Policy · Returns & Refunds · Warranty
