Thanks for all the advice on the other issues but now im really stuck,so again from the beginning, drove car back home after purchase 140 miles no issues, left it for a week and I knew battery was dead,so jump leads and car starts first time no rattles no funny noises but the oil light is on very dim ,on ignition it's bright red but on start up dim,turn it off and next day do a oil level check and oil is low,so i fills it up and starts again on jump leads and still oil light on again very dim again I don't want to risk let it warm up and see if oil light goes out incase its oil pump and engine goes bang,could it be just low battery as no oil light came on during 140 mile trip home,or bad oil pressure sensor,or bad oil pump,or something else help needed ,thanks

 

I had this on my 2007 STi, but mine was a bright flickering oil light for sometimes 15 seconds after start up.
Turned out to be a fractured oil pick up tube, very common, but may not be your issue. Sump off to replace this.
Maybe have a read here, 2003 models seem ok in the poll, but that doesn't always mean much : https://www.iwsti.com/threads/poll-b...x-stis.167221/

 

how often do you change oil

 

like I said not moved it yet ,was just a start from a jump lead start,so no oil change done as yet,its been parked since it got home,but oil light came on after a cold start,when it didn't during the 140 mile journey, that's what's confusing me,thanks