On 05/10/15 13:33, sms wrote:
On 10/4/2015 2:39 PM, Klaatu wrote:
According to NBC, the emission controls were altered when only the front
wheels were turning, as on a dynometer.
I don't know about diesels, but newer gasoline powered cars in
California don't use the dyno anymore. The levels are all read from the
sensors via the OBD-II port, at least in California.

It's trivial to detect that the car is not being driven.
No steering wheel motion, no compass variation, no accelerometer (if
fitted), no... you name it, I'm sure there's a long list of candidates.