Hi Tim, I'm pleased to assist you. If your sending unit s still working, no need to replace it. You can just connect it to this pump. If you're interested in this part, click the link below to continue ordering while supplies last. Your order will come with a 30-day post-purchase price match guarantee. Enjoy shopping! https://www.carparts.com/fuel-pump/drivemotive/repv314504?can=CPGG4850_CSQA_20230807

Hi John, This part you selected is a guaranteed fit for your 2000 VW Passat 4motion awd 6 cyl. This is our company's aftermarket affordable brand backed up with a 1 year warranty. This matches the OEM Bosch brand. To be accurate, please follow the steps below to check. To check the fitment please use our Vehicle Selector — which can be found towards the top of the homepage as well as all category, search results, and product pages — can help verify if a part will fit your specific application. To enter your application, simply select your vehicle’s year, make, model, sub-model, and engine type and click “Go.” Once your application is selected, you’ll see a “Guaranteed to Fit” badge if the part will fit, and we recommend that you also double-check Your Vehicle Fit Details as well as the Vehicle Fitment Information table on the product page.