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- USA
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- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 11 - Jul 16
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Description
Catalytic Converter for 2000-2004 Audi A6 Quattro 4.2L MagnaFlow 51664Overview: Keep the check engine light off with MagnaFlow OEM Grade Federal EPA Compliant Direct Fit Catalytic Converter 51664. With features including free flowing mandrel bent tubing and highly corrosion resistant, stainless steel construction, easily install this spun body converter yourself using the proper tools, no cutting or welding required. MagnaFlow's state of the art metrology department uses the latest 3D scanning systems during research
Overview:
Keep the check engine light off with MagnaFlow OEM Grade Federal/EPA Compliant Direct-Fit Catalytic Converter 51664. With features including free-flowing mandrel-bent tubing and highly corrosion resistant, stainless steel construction, easily install this spun body converter yourself using the proper tools, no cutting or welding required. MagnaFlow's state-of-the-art metrology department uses the latest 3D scanning systems during research and development, so you can be confident that your new part will fit and function like the original equipment. By replicating the OE spun body design, the single laser fusion weld greatly reduces the possibility of a leak, and our compact, low-mass design also allows for greater thermal efficiency.
Designed to fit the 2000-2004 Audi A6 Quattro and 2002-2003 Audi S6, this direct-fit catalytic converter also interchanges with OE parts 4B3 254 550 GX, 4B3 253 058 BX, among others.
Note : Not For Sale in California
Interchange:
| Brand | Interchange Part Number |
|---|---|
| Audi | 4B3 253 058 AX |
| Audi | 4B3 253 058 BX |
| Audi | 4B3 254 550 CX |
| Audi | 4B3 254 550 GX |
| Audi | 4B3253058AX |
| Audi | 4B3253058BX |
| Audi | 4B3254550CX |
| Audi | 4B3254550GX |
| Audi | 4B3 253 058 AX |
| Audi | 4B3 253 058 BX |
| Audi | 4B3 254 550 CX |
| Audi | 4B3 254 550 GX |
| Audi | 4B3253058AX |
| Audi | 4B3253058BX |
| Audi | 4B3254550CX |
| Audi | 4B3254550GX |
Application:
| Year | Make | Model | Submodel | Engine Size |
|---|---|---|---|---|
| 2000 - 2004 | Audi | A6 Quattro | 4.2L/V8 | |
| 2002 - 2003 | Audi | S6 | 4.2L/V8 |
Specs:
| Oxygen Sensor Location | Pre and Post Converter |
|---|---|
| Overall Length (In.) | 51 |
| Substrate Material | Ceramic |
| Air Tube Adaptable | No |
| Converter Quantity | 1 |
| Inlet Attachment | Bolt-On |
| Material | Stainless Steel |
| Outlet Attachment | Clamp-On |
| Finish | Stainless Steel |
| Series | OEM Grade |
| Main Piping Diameter (In.) | 2.25 |
| Subtitle | Federal / EPA Compliant |
| Title | OEM Grade Direct-Fit |
| Type | Direct-Fit |
| Body Material | Stainless Steel |
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.1 ★★★★★
Based on 189 reviews
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Product Reviews
★★★★★ 1
Useless
Color: White, Size: D20Plus
Well so far unable to actually use it to see how it works. I have to split my wifi every time I want to use it. It won't charge even when it's on the dock. When I push "charge" on the app it comes off the dock instead of recognizing that it's already on it and proceeds to roam around the house looking for the docking station that it just left. If it can't even find the docking station while sitting on it how can it properly clean the house? I just bought this after returning a defective AirZeen model. Looks like Shark may be the only way to go. Starting yet another return. These are useless
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Reviewed in the United States on March 27, 2026
★★★★★ 5
Great Cleaning Power and Super Convenient
Color: White, Size: D20Plus, Color: White, Size: D20Plus
The DREAME D20 Plus Robot Vacuum and Mop works really well in my apartment. The suction is very strong and easily picks up dust and pet hair from both carpets and hard floors. I also like the self-emptying feature with the large dust bag, which saves me a lot of time. The mapping is accurate, and the battery lasts long enough to clean the whole place. Overall, it’s a great robot vacuum for the price.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 12, 2026
★★★★★ 5
I am very satisfied with the overall experience!
Color: Black, Size: D20Plus, Color: Black, Size: D20Plus
The suction power is really strong. Daily dust, hair and debris can be easily cleaned up, and the ground is obviously much cleaner. Although there are no pets at home, it is enough for daily cleaning.
What I like most is its self-dust collection function. The 5L large dust bag has a large capacity and can be used for a long time without dumping garbage. It is really worry-free. It is very friendly to people who do not want to take care of the machine frequently.
The drawing is very fast and accurate, and the cleaning route is orderly and will not collide randomly. The APP is easy to operate, and the appointment and remote control are very convenient.
Generally speaking, it is very cost-effective, time-saving and effort-saving, and worth buying.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 30, 2026
★★★★★ 5
Good Robot Vacuum
Color: Black, Size: D20Plus, Color: Black, Size: D20Plus
This robot vacuum is really easy to use and very smart. After one cleaning cycle, it can remember the size and layout of the rooms, and it also allows you to choose different rooms for cleaning. It cleans very thoroughly, and when it finishes, it automatically returns to the dock to empty the dust and recharge. It has truly saved me a lot of time and has become a very helpful assistant at home. It also runs fairly quietly, so it does not disturb daily life too much. For people who are busy and do not have much time for housework, it is definitely worth buying.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 7, 2026
★★★★★ 5
Incredible robot.
Size: 11S MAX, Size: 11S MAX
I have had this vacuum for nearly a year now, running it on an automatic schedule every single day, and I am so grateful for this product and how it has improved my quality of life.
This vacuum and its automatic schedule has meant that I rarely see any dust or dog hair on my floor and I no longer have to take the time to vacuum. The amount of dust this machine collects is unbelievable- the photo I included of the yield is from HALF of a cycle.
Flooring/obstacles
I use my eufy on hard floor and short carpet and it works wonderfully. It does snag on high pile rugs so I try to put my bathroom mat up when I remember.
Eufy does get stuck on things so it took some time to determine what picking up I need to do before it’s “shift.” This has not been a nuisance, it’s more of a good motivation to do a quick cleanup.
Durability
Also, long hair is a challenge and I do have to cut it out of the brush head about once a week. I also recently replaced the brush head which was a great reset. The side spin brush also broke down over a few months and replacing that REALLY improved the power of the machine. I’ll be replacing it as soon as I notice breakage now.
Noise
I think it has gotten a bit louder over the year I have owned it. I used to be able to sleep through the noise, now it’s a bit too loud for me especially as it gently bangs against the walls (doesn’t scuff though).
Overall, this is a gift and I will never not have one for the rest of my life
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 19, 2026
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