LAItalian

Two months ago my 2018 GT3T had an issue with the stock exhaust, basically pressing the exhaust button wouldn't make any difference. Funny thing is, it wasn't completely quiet, it was sort of in the middle between quiet mode and open valves (this is a subjective impression, but it definitely was not on default mode).
Took car to Porsche South Bay, they told me I was lucky, it was just a simple issue (something like gas flow, not sure I remember correctly to be honest), car came back quickly.
Today, turned the engine on and exactly the same issue AGAIN! I recognized it immediately as the engine was noisier than usual at start and pressing the exhaust button made no difference. Driving same story.

I am frustrated but besides that, anybody has had the same problem?

evilfij

Vacuum hose probably popped off the valve.

GrantG

Or one of your valves is stuck (requires new muffler - not uncommon)

Maverick11

Sport exhaust is way more trouble than its worth especially in a gt3. Had issues on mine too. In fact this is my 3rd gt3 and 4th 911, and sport exhaust is the only problem I have had with any of them.

LAItalian

Could not agree more. Mo' buttons mo' problems...
And really what is the point of an exhaust button in a GT3??

n2cars

Yes, it's a known and unfortunately a common problem. One or both your mufflers need replacing. My first one was replaced at 900 miles then the second one at 1100 miles.