Posted on August 11, 2016 May 29, 2018 by FiTech EFI — 2 CommentsDo I need an external fuel pressure regulator? No, the Go EFI is the only system on the market with a built in fuel pressure regulator! Nothing to mount on your firewall! Post navigationPrevious post: Do I need a special intake manifold to use your EFI system?Next post: How do I set up the system for BOOST? 2 comments on “Do I need an external fuel pressure regulator?” Jack B. March 13, 2017 When using a external fuel pressure regulator on supercharged engine witch regulator do you hook up the boost reference line (vacuum line) external or the on on the unit that’s built in? Bryce - FiTech Tech Pro March 15, 2017 The regulator controlling your fuel pressure is the one that needs a vacuum/boost line ran to it.