96 gtb issues , constant flashing of CEL

So I have done a full swap and gone to drive my car for the first time and it has multiple issues firstly here are the specs of the car

1996 legacy gtb en20h running auto and vf20 turbos wagon jdm

So the issues are the check engine light has started flashing as soon as I put it in gear to reverse or go forward , next is the ticking noise from a little pump under the passenger car rhd vehicle and finally the BBOD is forever breathing or so it sounds which I'm thinking is the same reason the thermos come on and when it is driven it doesn't want to come onto boost

 

Problems I can think of . Car hasn't had premium fuel in it yet . Original tank of fuel from the na 2.0 and secondly I haven't changed over the TT fuel pumps

CEL does 3 long 1 short anyone got any ideas . Changed the fuel pump and only marginally better

You will want premium or else you will have knocking which could cause a CEL.

Found out one of the intercooler pipes wasn't on properly and so it fixed part of the problem next problem . What is the drive ratio for the rear diff on an ej20h running auto

When you did your swap did you use the trans that came with the EJ20? I'm guessing that you'll need the diff with the same ratio as your trans due to it being AWD. Sorry but I'm not sure of the front diffs ratio.