Actually, your NOx sensors were replaced under a BMW (the manufacturer) 10yr/120k mile extended warranty.

The federal emissions warranty - which would cover oxygen sensors or their equivalent, the NOx sensor in a modern diesel engine - is for 2yrs/24k miles. It covers a wide array of components and requires the manufacturer to cover the cost of repairs and parts if the vehicle FAILS an emissions test. Generally, it is used to cover the cost of these parts even if they fail when not part of an emission test.

Other specific components - a much smaller list to be sure - are covered by an 8yr/80k mile warranty.

I'm kind of still thinking that the SCR is not the problem. My service advisor started the same BS with me when I brought it in for a locked in "999 miles to No Start" and 4D16. He wanted to replace the SCR, started telling me tales of woe if I didn't do it, that I'd be back. Clearly the problem was with the active tank - covered under the BMW extended warranty - and the NOx sensors. I insisted that those be changed and the dosing module for good measure. Really fought me on the NOx sensors. Anyway, that was almost 40k miles ago.

After that interaction, the relationship, or rather, the dynamic between him and I changed and he's much easier to deal with. You can be assured that with a little research, you will know more about any single vehicle than any service advisor.

__________________
8/2011 X5 xDrive35d Sport, Black Sapphire Metallic, Black Nevada Leather, Fine Burr Walnut Trim
2/2001 M5, Jet Black, Exclusive Complete Black Walk Nappa Point Heritage Leather, Black Cubic Trim