John German stumbled onto VW's cheating. The fact they managed to get away with it for so long is testament to loopholes in the testing procedure. The fact that VW was alerted and continued to cheat is astonishing.
German published the research in May 2014 and handed it over to the Environment Protection Agency (EPA). “There was an expectation that they would find out what was causing the higher-than-expected emissions,” he said. “We did send a courtesy copy to VW to say ‘vehicles B and C are your vehicles and you might like to know’, we had no response.”
There was no response from the EPA either, but keen-eyed German noticed an EPA press release in which VW agreed to recall almost 500,000 vehicles in December 2014 to reinstall software, which it said would solve the higher-than-expected emissions.
However, a couple of months later the California Air Resources Board (Carb) carried out spot checks and discovered that the “defeat device” software – used to dramatically reduces nitrogen oxide (NOx) emissions only when the cars are undergoing strict emission tests – was still present.
“That is actually the single most inexplicable thing about this whole business,” German said. “VW had a chance to fix the problem, and they continued to try and cheat and do what they had done. That’s just amazing.”