I have a my98 uk impreza turbo. The other day i checked what boost the car was running as i had noticed the warning light flicker on and off a couple of times on the boost guage. I've got the Defi link system so i recorded a blast through the gears and after peaking at about 1.2 bar it was dropping to about 0.95 to 1 bar (Roughly standard??). A friend recommended a type of cleaner which i flushed through the air intake system; when i set off the car stalled & then on restart kicked out loads & loads of white smoke. The car now seems to be a bit more responsive and idles very smoothly, but i noticed a big difference when booting it as it now hits between 1.3 & 1.4 bar ( Defi 'motor stepping drive' guages, how accurate??) and stays there until the fuel cut kicks in. it's making it quite hard to drive quickly as i constantly have to watch the boost guage and cannot put my foot right to the floor!! As far as i know the car is only lightly modified with dump valve, blitz filter, full stainless exhaust (no cats - could this be a big part of the cause??). Or do you think it may have been chipped? Although i can't undo the screws that hold the plate over the ECU in the passenger footwell, and they don't look like they have been touched before.