Excellent review by Adrian Colyer for those interested - https://blog.acolyer.org/2017/06/20/how-they-did-it-an-analysis-of-emissions-defeat-devices-in-modern-a

Excellent review by Adrian Colyer for those interested - https://blog.acolyer.org/2017/06/20/how-they-did-it-an-analysis-of-emissions-defeat-devices-in-modern-automobiles/ https://blog.acolyer.org/2017/06/20/how-they-did-it-an-analy... Also, the book How they did it gives insightful glimpses.