So on my 2001 the water meth controler and manual boost gauge match right up. The iQuad shows 1psi when the other 2 are reading 5-6 psi it starts to read closer once I’m above 30 psi. Bad MAPS sensor? What do y’all think

I'd say the map sensor is a good place to start. Also make sure your jumper in the ADR box is set properly. 

 

See this post:

 

Make sure you're up-to-date on the latest software in the quad box, they were playing around with PSI offset and you may have an older version. Mine is off about 2psi, manual boost gauge will show more than quad until higher PSI than they equal out. 

So I replaced the MAPS sensor and no change. At 5psi on manual gauge I show 1psi on the iQuad. I just bought the iQuad 2 months ago. I’m using the V2 1998-2002 version 2.7. Should I try the V2 Quadzilla Only it says version 3.94?

No,

 

The quadzilla reads map values from the ecm until 16 psi.  this is likely just the way your truck is some late trucks seem to have lazy map outputs from the ecm.  As long as map increases smoothly and is not jumpy then there is no issue.