I bought my car at 90k. The turbos were rebuilt at 85k (fact). I did the timing svc at 100k. I have the APR bi pipe, baily MS DV, GIAC Flash, Blitz DD TTBS (turbo timer and boost gauge, reads in kPa).

So now you know the history and setup, so this is whats going on now....I was getting on it on the on ramp one day and it would not build over .6 kPa (8-10psi) the GIAC flash is supposed to run about 16-18psi. I checked the data log on the gauge in the peak read 1.35 kPa (about 20psi!!!). I think this blew the turbo.

When it first happened i thought it was a simple boost leak. I had it tested and there was no leak! then i pulled codes and it came up with two (evap bull ****) so we cleared them. The car still would not make over .6 kPa and the throttle responce is not there.this makes methink the car is now in a safe mode for some michanical reason; not showing upforthe lack of a sensor, turbo, DV, etc...

I checked the DV and they are good, no boost leak, no codes, the car is in safe mode. what do you guys think? My only other guess is the turbos craped out.

Your EVAP should be checked out if it's pulling codes.

http://forums.audiworld.com/s4/threa....phtml#2801632
that was JUST posted like 30 minutes ago ,kinda funny.

Does your turbo screaming at all? 'dentist drill' noise?

when we first pulled the codes it came up with two. and then we cleared them. I dont know if that would cause the software to releace it from safe mode or not, but the codes were:

P1556 Charge Pressure Controle negative deviation
and
P0442 Evap controll system, Small leak detected

we cleared the faults, ran the car and they did not show back up though. weird.

As for the turbo, I dont hear anything that stands out, maybe the most faint whine. but i dont know for sure. it is not alarming to me as of yet.

charge pressure control negative deviation is a boost leak IIRC.

there could be a small leak in the fuel filter or another gasket issue.

whats IIRC? Do you think this is what is putting the car into safe mode?

IIRC- If I remember correctly
I have not researched that problem or havn't read about it so I am not sure, sorry!

first, run a VAG-com boost check. could be something wrong with the N75....check that out first, they are pretty flaky. also could be the wastegate, not sounding like it though. Fix that leak asap.

I im taking it to AUDI tomorrow to get it fixed.
If it were the waist gates wouldnt the boost spike and not be restricted?
Whats the N75?

the n75 lets the boost go kind of like a boost controler

so what is the fix? **** can or replace it?