My 997.1 Turbo (26K miles) boost will not go over 9 PSI... engine sounds normal, no CEL has been set. Only mod i have are vividracing straight pipes which had been installed last summer and never had any issues, stock tune. I will be taking the car to the porsche dealer on Monday, but would like to know what could be wrong. I did have my local garage Porsche tech look at this yesterday but he could not see anything obvious with it like loose hoses etc. He did not have a Porsche diagnosis tool to dig deeper. If someone has experienced a similar issue feedback would be appreciated... Thanks!

 

You might try the 997 turbo forum for better response. There is also a technical forum.

 

https://www.6speedonline.com/forums/997-turbo-gt2-58/

 

Thanks !