SCR systems are very expensive in modern VWs as well. Especially to repair. With the additional pressure on the engine because of restrictive exhausts engines a

SCR systems are very expensive in modern VWs as well. Especially to repair. With the additional pressure on the engine because of restrictive exhausts engines also don't last as long. EGR systems on diesels are known to gunk up. VW used SCR systems since 2009 if you didn't know.