There are a few words at
Scroll down to the 6th full paragraph under "The California Model".
It appears that either the test station must have a 4-wheel dynamometer,
or your vehicle will be granted an exemption from the dyno test and will
be subject only to a simpler idle test.
Lots of cars will present this dilemma to the inspectors - and more
every year. Any vehicle with AWD (such as all Subarus, for instance) or
a traction control system. Fully automatic 4WD would seem to be part of
the same group.
The issue is well known, and the emissions test shouldn't cause you any
problems, regardless of whether they use a 4-wheel dyno or give you an
exemption. On a larger scale, the number of exemptions would seem to be
growing as TC and AWD become much more common. This may lead the
states/feds to mandate that more inspection stations be equipped with
4-wheel dynos, which adds to the cost.
Let us know what happens.
> Havn't seen anything about this on the board, but I'll be coming up for
> a smog test here in Calif where we now have to be on a dynamometer for
> the test. I'd like to hear from someone who has been through this. I
> have apprehension over the 4WD issue when only 2 wheels are on the
> machine. Any potential problems? (2001 4WD AUTO HIGH LOW)