Fix for Subaru GR Stumble? FPR Install! 

What were the symptoms of your stumble? Mine are at 2500-3000 under slow acceleration or cruising at those rpm

You have 3/8" quick disconnects and you needed 5/16" quick disconnects. I'm sure you've figured that out by now. You need to get 5/16" disconnect with the same sized barb you have now though, which should also be called 5/16". Quick disconnect sizing gets weird due to ID and OD on nylon line vs rubber hose etc. Also just feel lucky this has the external FPR instead of being regulated at the tank like the BRZ or other NA cars.

When is Tony starting his own channel?

You need the kind of connectors that go on that part.

you can either stumble or spray fuel all over the engine... Its what makes a Subaru, a Subaru