i have a problem with my factory turbo gauge and subaru does not seem to be able to figure it out. i am hoping that the vast pool of knowledge that is nasioc can help me.

a couple of weeks ago i took a drive up a nearby canyon, parked my car for a few hours, and then drove back down. on the way up, my turbo gauge read just fine, with a top boost reading around .09 mPa. however, on the way down and ever since, the needle tops out at .04 mPa. i took it in to the dealership, and they tried the following:
replaced the turbo gauge, twice,
took apart the exhaust around the turbo,
checked the waste gate and blow off valve, and
replaced the pressure gauge and harness.
they had the car for 2 weeks and spoke to the tech line numerous times, but when i picked up the car yesterday, the same problem exists. according to the service tech, they don't know what else to do.
help! any thoughts?

It seems like you are only getting wastegate pressure. In your list of things that were checked/replaced you don't mention the boost control solenoid, if this is stuck closed you will get only wastegate pressure as your maximum boost. Ask them if they checked this solenoid, and if not gently ask them to do so. If they didn't look at this it's not a good sign regarding that dealer.

thanks for the reply, mulder.
i called and talked to the mechanic, and he said that he had checked the solenoid and even swapped one from another car. no luck. he seemed to say that it may be my turbo just not putting out the boost. he indicated that soa had him test the turbo output, and if it was between 7.1 and 9.4 psi (which it was, barely), then it is within specs and they wouldn't replace it. that seems odd to me, considering that i was getting .09 mPa consistently, which i belive is around 14 psi.
thoughts?

Well the possibilities are a problem with the boost control system (which seems to have been ruled out), or something with the engine that is preventing the boost from building up or allowing it to leak out.
Are all your hoses and fittings secure on the manifold and intake? Any strange noises?
Does the vacuum read normally or has that changed as well?
I suppose a failure of the turbo itself is another possibility but you say they tested it. How did they do this exactly, if you know? It's a PITA to do, but if the intake hose is disconnected from the turbo inlet you can reach in there and spin the shaft to see if it turns freely. You can also see if there are any marks where the turbine is contacting the housing (you'd probably hear this too).
It just seems strange that this happend all at once, which would indicate something having failed or come loose, and they can't find anything.

I can tell you a way to "test the turbo"; however, DO NOT DRIVE AROUND with this settup for long (or at all)

simply unplug the little hose coming directly off the turbo nipple...
the further down you foot goes the more boost the car WILL make, peroid. DO THIS SLOWLY

*** the car can & will boost past "safe" psi on command***

If the car still will not boost past (or near) 0.09Mpa then there is an exhaust/turbo/wastegate/IC hose/BOV problem

If you get on it & the PSI will go to 0.09+++ on command then you have a ECU/hose routing/boostcontroller problem

Again DO NOT DRIVE AROUND LONGER THAN A SINGLE RUN ON A EMPTY ROAD IN THE COUNTRY
There is a "fuel cut" when you hit somewhere near 17-18PSI, so there is somewhat of a safety guard built in...
or
You could just find a better mechanic that has a clue how the system works...

thanks mulder and GLwagon for the advice!

i was fortunate enough to be accomodated with an afternoon appointment with trey at cobb tuning here in salt lake! within an hour, he had it figured out. it was a connector fitting in the turbo line hose that had somehow melted shut on one end, cutting of any flow. he put in a new one and *bam*, the boost was back up to .09mPa!

woo-hoo! my car is back! trey figured out in under an hour what the dealership (who were very kind and tried hard) in conjunction with the soa tech line couldn't figure out over the course of two weeks!

go cobb!

willie bill congrats. :)

way da go Cobb Tuning! :D its sad how some certified dealers lack knowledge of their own car and cry ' i dont know wat else to do' when a non- factory certified enthusiast technician jumps in and 1hour later bam! all fixed.

i guess this means subaru does not train their techs very well...