[John Rogers]

I would two things when told about this, first check with the California CARB website which is a real maze of rules, references and more rules and second, check with a trusted Porsche repair shop that handles getting Turbos smog checked to find out their information on this. When we had our 1987 930 that was modified somewhat, every two years we took it to Black Forest in San Diego for a tune up, put the cat back on, etc, etc and they would get it smog checked. Then afterward it would be reverted back to it's modified form. They used a smog shop that was familiar with 930's since the rolling test specified the RPM range and speed but an early 930 with a 4 speed transmission could not do that so we always got a waiver and it passed.

There is a small bit of info on the CARB site that mentions the highway tests and road side tests are mandatory, no choice in the matter it appears?