A half-million diesel Volkswagen models have been cited for emissions violations. Here’s our handy guide to what’s happening.

At the 2008 Los Angeles Auto Show, the 2009 VW Jetta TDI Clean Diesel was crowned the 2009 Green Car of the Year by Green Car Journal. The Jetta gives another eco-friendly option for those looking ...

A second NOx sensor downstream of the catalyst also will be added, allowing the emissions system to operate in an improved, closed-loop mode thanks to another forthcoming software update.

This will involve installing a second NOx sensor and a new or replacement diesel-oxidation catalyst. In March 2017, VW received approval to sell these cars, of which there are approximately 12,000 ...