Zenbong

So i recently bought an 06 XT forester, complete with rebuilt motor, 257 short block, vf34 and a tune running 19psi and 193kw. I recently got defected (australias way of screwing you over) for running a bigger turbo without engineering certificate, and requires me to refit a stock turbo TD04. Upon refitting the TD04, i started the car and it begun to idle rough, making a knocking sound (cant be rod knock because it ran perfect when the motor was pulled). Eventually the car sounded like it wanted to give out after idling for 30 seconds. Is there anyone that can suggest why it is doing this? Is it the tune causing the td04 to not function with the engine properly?? PLEASE HELP!

Cheers

Hi to all members of subyclub.

So a few months ago I purchased a 2006 Subaru Impreza R S with the 2 litre DOHC EJ204, and immediately i was faced with poor acceleration and jerking. I had the engine light come up for my front o2 sensor, so i had that changed. The problem however was still occuring, but only under moderate acceleration, or going up small hills. I changed all 4 spark plugs and put a brand new k&n filter in. After driving around for a few days the problem slowly comes back (best as i can describe it). The strange thing though is when i disconnect the battery and reconnect then drive around, the problem fixes itself (or becomes less noticable) but a few days later its back. I had suspected it could be the fuel filter, but am not too sure.

Anyone else have similiar problems like this? I should also add it has done 273k kilometers.
If someone could give me advice i would greatly appreciate it.
Thanks