If you have done on-board computer scan after seeing check engine light on the dashboard and your car is showing any of these error codes P229F62 P229F P229e P2202 P2200 U029E00 U029E U029D00 U029D, it means that NOX sensor has failed. Xenon4u offers Audi 8R0907807G Continental 5WK96728B NOX Sensor. It is always recommended to fix this issue as soon as possible to avoid any damages to DPF filter, otherwise diesel particulate matter or soot can clog filter and it will cost you thousands to fix. Error cleaning may be required, but just once after fitting new NOX sensor, it can be done by you. For more information visit our website.