[Biturbos4] HELP!!! Troubleshooting DTCs w/ EPC light

[John]

David Kavanagh wrote:
 > Thanks. I did check for boost leaks (see this :
 > http://home.rochester.rr.com/dak/leakcheck/)
 > I ended up replacing the leaking valve cover gasket. I haven't tried to
 > re-pressurize the system since. I also wonder if it is really valid to
 > pressurize at the point I did. I mean, the part between teh MAF and the
 > turbo intake is generally under vacuum. Still, 10 psi can't be a bad
 > thing to test with. If it leaks at that pressure, chances are I'd have a
 > vacuum leak when running!

I was baffled by your fix until I noticed that your said: "...the part between 
the MAF and the turbo intake...". While the valve cover leak was probably a good 
catch, I'd assume that won't affect your problem. Don't most cars, including 
Audi, have any number of check valves and air hoses between the crankcase, fuel 
vapor system and the intake to burn vapors for emission control?

John