I got a p0446 error code
 

My service engine soon light has come on and after buying a code reader I got the p0446. Evaporative emission system vent control unit. Whats gona be the damage on this?

What year? What engine? What transmission?

P0446: Purge airline is blocked or high flow resistance in the EVAP canister.

The car is 1999 2.5 automatic, any idea's on how to remedy such a problem ie.. parts

First you need to check both the purge airline and its control valve to make sure it is not blocked by carbon build up, if it is, blow it out with compressed air. Reset the code and see if it returns. If it does, you need a new EVAP canister.

Sometimes I think I can smell gas in the car when driving. Is the blowing out the purge airline something that can be done by me with a can of air?

The gas smell is a signal that the EVAP system is not working correctly. I see no reason why a can of air won't work.

Ok weirdest thing happened today, the code was on when leaving work. Went to fedex to pick up a package and when I got back in the car the light was off.

If the car develops a n emissions problem, it throws a code; if the problem then clears itself, eventually the code will as well.

Thanks again for responding with your logical replys JFP. I am assuming the problem has corrected itself then?

I made an appointment with my local Porsche dealer to have it looked at on Friday and they said it would be $75 just to have the code read to me. It took a week with my schedule and theirs to get me in and maybe I should ask about that 60k tune up thing I have read about on here. Any idea on a general pricing give or take a few $$?

My boxsters into the high 60's in the miles and I just bought this before winter hit and see no record on the service history of this ever being done.

Yes, it corrected itself, but it can return if the problem does as well.

Porsche's "60K" maintenance service is pretty extensive in what it covers, and typically runs in the $1200-1500 range.