MagnaFlow's OEM Grade manifold catalytic converter is the close-coupled replacement for the factory unit on the M54 inline six, installing with hand tools and no cutting or welding. The spun body replicates the OE design and its single laser fusion weld greatly reduces the chance of a leak, while the compact, low mass shell lights off quickly and holds heat where the catalyst needs it. High strength 16 gauge 409 stainless steel tubing and 308 stainless steel MIG welds resist corrosion, and mandrel bent tubing retains the factory flow path so fuel economy and driveability stay stock. It interchanges with OE parts 18 40 7 514 504 and 18 40 7 508 760, and the included gaskets and hardware avoid reusing corroded factory fasteners.
| Type | OEM Grade Federal / EPA compliant direct-fit manifold catalytic converter, spun body |
| Position | Primary (close-coupled manifold converter) |
| Material | 16 gauge 409 stainless steel tubing, 308 stainless steel MIG welds |
| Emissions | Federal / EPA compliant; for OBDII Federally registered vehicles with California or Federal / EPA emission systems. Not legal in California. |
| OEM Replacement | 18 40 7 514 504, 18 40 7 508 760 |
| Installation | Direct fit, no cutting or welding required; gaskets and hardware included |
| Quantity | 1 |
| Part Number | 51816 |
This part fits:
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2001-2005 | BMW | 330xi | Base |
| 2004-2005 | BMW | X3 | 2.5i |
| 2004-2006 | BMW | X3 | 3.0i |
Shipping: In-stock orders placed before 3 PM EST ship the same day, and everything else ships within 24 hours. Standard, expedited, and overnight options are available at checkout. Backordered items ship as soon as we get them back in stock. Contact us for lead times. See the full Shipping Policy.
Returns: 30-day returns on new, unused items in original packaging. See the full Refund Policy.
