So my 2002 wrx started this weird issue last week and i have been trying to find out what could cause this and wanted to see if anyone on here has had this issue or can guide me a bit.I have not gotten any CEL.When i go WOT in 3rd,4th & 5th gear my boost gauge goes up to .1(16)lbs then goes down to the .05 then back to .1(16) back to .05 then goes to .15 and just bounces and the car feels like im depressing and pressing the gas while WOT i can feel the car get boost lose boost then get boost lose boost.So far i have changed out all the lines from the EBCS (2 lines) & the line after the T to the turbo and still have the issue.What ive read was EBCS,Fuel pump,02 sensor or maybe even the Cobb AP could cause a issue??Maybe a Vac leak?I have been searching to find out how to test the EBCS but no luck here are my mods.I can take vid with cam if needed to show exactly what it is doing,i also noticed that it has been killing me on gas aswell,is that a sign of the pump?
JDM Sti V7 up pipe
Cobb Sf intake
HKS Down pipe
Tanabe Racing Med exhaust
Cobb AP Stage 2 OTS map V3.10 Map