Yes you may obtain a pre-test however this is an identical test to the
actual smog inspection except that the results of the smog inspection are
not held against you. In other words say for instance the vehicle produces
"Gross Polluter" results, under a regular smog inspection gross polluter
results would subject your vehicle to test only smog inspections for the
next several smog tests to come.
If the vehicle produces gross polluter results under a pre-test, the vehicle
will not be subject to test only inspections and can continue being
requested to undergo regular smog checks. Now this only applies if the
vehicle has not been directed to a test only facility in the first place. If
the DMV has asked your car to get a smog check at a test only center then
getting a pre-test really makes no difference.
What I would really recommend is that you simply find a smog test only
center that offers a free re-test, and this way even if your vehicle does
fail the test you have a second test to utilize after further repairs.
However it sounds like the repair you made to the intake manifold gasket
should clear things up specially since you noticed a performance increase
already.
