"sms" wrote in message
...
On 9/20/2015 3:49 PM, sms wrote:

snip

I had a smog check this morning on a 2007 Camry. The shop had a new
machine for newer vehicles. Since September 2013, 2000 and newer vehicles
no longer get tested on the dynamometer and no longer get a probe shoved
up their tailpipe. The whole test is done via the OBD-II port (as well as
a visual inspection).

For diesel vehicles you can see the details he
http://www.smogtips.com/diesel-smog-test.cfm

So clearly VW was not just looking at wheel rotation, they probably turned
on the emission controls whenever they detected something reading the
sensors. I wonder if an ELM327 transceiver or a Progressive "Snapshot"
would have any effect.

Here's an interesting point. It seems CA has portable roadside emissions
checkpoints that measure the emissions as you drive. I wonder why they
haven't seen a major problem with VW vehicles as they pass these
checkpoints?

Maybe it is a minimum difference between a properly working system and a VW
in the fuel economy mode? Like someone else said - is the nominal emission
near zero and 10 to 40 times worse is still an extremely small amount of
NOx.