Emissions Problem
 

I have an '89 911 Cab with 44K miles. I recently moved to MA and failed my emission inspection (hydrocarbons too high). I haven't had much opportunity to drive the car (biz travel) and I garaged the it for the winter (4 mos). The porsche dealer says drive the car hard for 30-days and bring it back for another emissions inspection. Its now 40 days later and I'm smelling an odor almost like a rotten egg when the car is running hot. Is the problem in the catalytic converter? Is this the carbon burning off? I'm sensing a bit of hesitation coming out of 1st or 2nd and small amounts of backfire. Thank you in advance for the help.

To make it that rich I would suspect something like a bad head temperature sensor or an air fow meter that's way out of adjustment.

The rotten egg smell is an indicator of high sulfur content in the fuel. I don't know what the effect on the engine would be.
Post all the numbers of your emissions test. Even those that meet the spec are needed to diagnose the problem.

Have the air to fuel mixture checked. Your symptoms sound like your mixture is too rich. Also, when was the last tine the O2 sensor was replaced?????

kw