Hi,
Can any one help me please?
I dare say this is obvious to some but I’m a bit of a novice and just wanted some guidance.

I have pretty much stock 03 wrx just decaf up pipe n prodrive exhaust with forge box.

Recently had a boost gauge installed and noticed I only get max 0.5 bar even in higher gears going up hills. Also vacuumed pressure at idle is only -0.1 bar.

Most posts I read say
1. Leaks on air / vacuumed lines
2. Boost solenoid
3. Waste actuator

Took it to my mechanic n he recommended compression test on engine. Seemed odd that no one else recommends this.

So

Can bad cylinder compression cause low boost pressure?

Thanks

Mike.

 

Update, have checked air lines all seem fine pill is present and in correct location. Connected the 2 green connectors under dash and can hear the boost solenoid clicking so presume this is fine. Will try and get compression and air lines pressure tested today.

I still don’t understand how cylinder compression could affect boost pressure?

Any advice would be appreciated

 

Still at a loss, compression test came in within tolerance...

The actuator arm looked a bit corrodedbut moves with a bit of force, used some wd40 and still the same.

Going to buy a more reputable boost guage but I still think the read will be low.

Any advice would be great, feeling like I am using this form more to keep my sanity than get an answer at the moment

 

Still unsure but today have disconnected actuator and got full boost!

Solenoid cleaned and gave it a good blow seems fine stope and starts allowing pressure.

As the actuator waste gate arm is corroded I am tempted to say this needs to be replaced but is there anything else it could be?