I did not come across a thread in my search on swapping out the OEM 3.8 Bar FPR to 5 Bar FPR, so here it is for a 997.1TT

1 Remove fuse 1 and 2 from column D and try to start the car, if it does it will
stall shortly.This will relive pressure in the fuel system and you won't have fuel
gushing out when the FPR is removed.

2 Remove Air-box and its connection to MAF sensors

3 Remove Y-pipe

The FPR in on the passenger side right underneath the 4 inch flexible pipe\rest hard pipe that connect to the turbo.
Lift up the 4 inch flexible pipe as much as you can and undo the clip (looks like a big hair clip) that holds the FPR in.

Disconnect the vacuume line that is connected to the FRP, has a clip but slides out with the clip on.

Gently pry out the FRP using the vacuum nipple for leverage.

Oil the O-rings lightly with fresh motor oil and slid the 5 Bar FPR in.

I used a 9" 1/2 extension rod as leverage to push in and seat the 5 Bar FPR in.

Reconnect vacuum line and reinsert the clip.

Reconnect/install air-box and y-pipe.


It took me 3 1/2 hour to complete as I was not seating in the 5 Bar FRP in completely and the clip refused to go on.

I can do it in 2 hours now having done it once.

 

As a new Turbo owner, Id love to know what you are talking about.

 

Some tuner require you to upgrade the stock(3.8 Bar) Fuel Pressure Regulator to a 5 Bar when you are reach the limits of stock fuel injectors.

This enables the the tuner to flow more/lower duty cycle at a given RPM.

I did this to enable me to run E85 tune on stock injectors.