Low Boost?

[QSHIPQ at aol.com]

The factors that affect boost are:
CAT
knock
WOT switch
Engine temp
Altitude
air leaks (pressure type = hoses or vacuum type = bypass valve)
bad turbo

I'd make sure that the temps senders are sending the proper signal.  Also, ck
that the WOT switch is sending the proper signal.  O2 sensor LIFE is affected
by application, they all (not referring to wide range here) *do* the same
thing (.1-.9v), and are interchangeable in that respect.  Sometimes sampling
rate can be affected (too many slots), but I haven't found that to be true
using a variety of O2 apps on audi turbo cars over the years.  Vag should
eliminate 02 function quickly, you should be hovering at .9-1.01 lambda at
idle.  A bad O2 will either fluctuate wildly or stick at a low value when the
throttle is applied for 20 seconds or so.

My bet is the system is *working* properly.  Which means that an 'input' to
the computer isn't within proper range for full boost application.  Temp
senders are famous for causing this problem, so are WOT switches.

HTH

Scott Justusson