Hunting issue
 

Hi everyone I have recently brought a 2003 Impreza sti type UK and it seems to hunt ever so slightly on idle but when you drive the car it jerks a lot below 3k after that it seems fine , any ideas where to start ??

hunt as in misfire ?

No as in the revs go up and down a little on idle but when you drive it's alot worse and it jerks but not misfire

hummmmm

could be idle control valve
throttle body
hole somewhere in the air/boost system
a few things lol

can you get a code reader to it ?

I've changed the throttle body basket and the idle control valve gasket and still the same , going to plug it in today and see what that says

so I found a split in my turbo intake pipe so I replaced that and it has made it worse up to now I have replaced

Turbo intake pipe
Maf sensor
Throttle body gasket
Idle control valve gasket

Anyone have any other suggestions

Do you have a oil catch can? I've had the same problem. Sorted it yesterday. The guy who previously had the car hadn't emptied it for a while. I emptied it yesterday. Full to the brim! Cleaned out can and hose. Car now has a steady idle and no hesitation

The car is totally standard it's a 2003 sti type UK

Can't see why the new Intake pipe would make it worse though