EJ20G boost problem
 

Good morning fellas !
I have a boost problem with my gc8.It's a '93 JDM version with the TD05,usually boost came at around 3000 rpm,now it comes at 4500++ rpm.I tried with another fuel pump,ECU reset and nothing helped.I didn't find any boost leaks(I'm gonna look again later today)...I'm running only 100 octane fuel.ECU check gives me errors 21,23,24.When I let the car go by itself on downhills and it's put on gear engine check lamp goes on,when I press the clutch and let the rpm gauge fall down,it goes off.Another thing is that the car burns huge amount of oil,the previous owner tapped all the "eco" pipes,and I'm going to connect them again today...BUT this happened before and the car was still going okay lag wise.

Can somebody tell me where to start first ?

first i would sort out the fault codes & get them sorted, than reset the ecu, also check spark plugs & coil packs

also if its using alot of oil, surely you have a gasket/engine issue?

codes i believe are as follws:
21 - Engine coolant temp sensor
23 - MAF (mass air flow unit)
24 - Idle control valve

also would be worth cleaning the three port solenoid out

I noticed another strange thing - boost problems seem to stop when I drive the car like mad (redline,wide open throttle,at least 1 minute in full boost)...and when I drive normally afther that it's getting laggy again.
Engine check light sometimes turn on,when redlining...
Also,I think my spark plugs need to be replaced,the car is vibrating like a 69 charger when waiting for traffic at idle.