I had a fuel injector go bad the other day on my 2002 XG350 - apparently it
was spraying gas all the time.  I was able to limp home and then got screwed
by the local garage when they fixed it. $600 to replace a fuel injector and
do shoddy work like forget to plug one of the electrical connectors back
together, leave the back 7 bolts on the plenum lose, forget to tighten one
of the hose clamps on the air snorkel altogether, and over tighten the oil
filter when they changed oil (that I didn't authorize).  But all that is in
the past, or is it?

A few days later the check engine light lit up and the code is P0401, EGR
flow insufficient.  Needless to say, I don't want to bring the car back to
that garage (I'm sure they could scam some more money out of me - they were
really slick).  From what I could get out of the web site and my service
book, this almost looks like a low vacuum problem rather than an EGR valve
problem.  Any recommendations as to how to fix it?  I have a second 2002
XG350 that I can swap parts back and forth with.  Also, If the EGR valve is
a suspect, how does it come off?  There are 2 bolts that hold it to the
polonium, but then there is a big nut connecting it to a tube...looks like
there isn't enough room back there to get a wrench on the nut.  If the nut
does come off, is there some sort of thread sealant required when you
re-install?  sparkplug antiseeze compound maybe?  Also the manual stated
that the EGR gasket should be replaced.  How important is this? - I've done
spark plugs a couple times and have never bothered with the EGR gasket.

Thanks

Dan