Hi,
I have a GC8 STi V5,
recently i have noticed the boost gauge is only showing 4Inhg vacuum at idle and only boosting 4psi max
(Autometer Gauge)
Now when i first got the car it was showing 21 Inhg vacuum at idle if i remember correctly and boosting 14.7psi
I have tried a different gauge when is brandnew and still shows the same readings and also swapped out the vacuum hose to the gauge
It idles fine and drives fine...
I have checked over all the vacuum hoses and they seem to be fine.
What may cause this?
Thanks