M103s do not have a valve as part of the PCV system.

If the engine is well maintained and appears and feels to be in good working order, there are no specific actions that you need to take before the test.

These engines are very sensitive to temperature. CA has tagged them as "high emitter profile." Long periods of idle cause the converter to cool off and lose oxidation efficiency, which can cause excess HC.

In most of CA we have a two speed loaded dynomometer test called "acceleration simulation mode" or ASM. My suggestion to all is to thoroughly warm up the engine with at least 20 minutes of driving, preferably with a freeway jaunt. Go to a drivethrough place with a short line, and keep the engine at 2000-2500 until the tech is ready to take the car.

As part of the CA procedure there is a "tire dry procedure" that is used on wet days. The tech runs the engine at about 2000 on the rollers with no load for about a minute, and this will heat up the converter, so testing on a rainy day and requesting that the tech run the tire dry test will usually keep HC below the limit, though rainy days are rare for most of the year.

If you have a failure, post the type of test and all the measured gas quantities including O2 and we'll help you diagnose the problem.

Duke