Boost testing doesn't get talked about much on the forums and yet leaks are very common and exaggerate symptoms of poor starting, idle, max boost and boot lag.
Disclosure: USA shoppers... Every auto parts store in America has a tool like this on their shelves. I only offer this item because you will need something like this to perform the boost testing that is so often needed to get your 951 back up to peak power with minimal boost lag. This particular tool (which is HF item 62637) also has some helpful fittings and a case.
This product was added to our catalog on Sunday 12 February, 2017.