Boost gauge problems

["TM" <mizutanit@mindspring.com>]

Hi listers,
I have a VDO boost gauge in my A4 1.8T. I recently removed the gauge to
paint the gauge housing, unhooking the two electrical wires and unscrewing
the vacuum line. Ever since doing that, I get a much lower reading.

Is there a "recalibration" or some sort of reset necessary when reinstalling
the gauge? I checked for leaks, and I don't seem to find any leaks. The
line has a threaded coupling that is sealed with Teflon tape.

For whatever reason, I think the gauge is reading about 5 psi low- I get
about 22 vacuum at idle when I used to read about 20, and max boost now
only goes to 15 when it used to overboost to about 20 psi.

Any help diagnosing/fixing this problem is greatly appreciated.

Thanks,
Taka Mizutani
99.5 A4 Avant 1.8TQMS