New too me spicy tuning issues


2003 Mazdaspeed protege
So I recently purchased a spicy orange protege and it's been slightly modded. It has among other things, pope manifold and downpipe, street unit side mount and piping, corksport 3in exhaust, relocated maf and a forge vta bov and a new wastegate actuator. It runs ok but is has it's issues. Chief among which is when you get on the gas and into boost its surging, not boost or fuel cut throw u into the steering wheel harsh but it just feels like it's dropping them gaining boost but the gauge stays steady at just under 8psi. No codes, changed the o2 the maf, rod twice, knock sensor, can sensor and a set of 1 step colder plugs with new wires oh and a walbro 190lph pump. I'm at a loss with this thing. I have a haltech sprint 500 for it and a gm map sensor but id like to get it running decent before I swap in an ecu.