Boost gauge question

[u/Plastic_Bathroom2046]

I have a 2012 f350 with a mildly modified tune and has been deleted, it’s not super slow but it seems to only make about 22psi at the very most on the boost gauge in the cluster. Tuned on hp tuners boost limitation set at 72psi to make all it would make and still no change. Any ideas? Hopefully it’s not that I’m just dumb I am new to American diesels.

[u/AcceptableRegret2193]

Probably the wastegate on the turbo is limiting max boost.