code 105

[dmh]

'95 G20, 120K, auto
The check engine light was on.  I pulled a code 105, which according to
a source on the internet is a problem with the "egrc circuit."  My
Haynes Primera manual was useless for further diagnosis.  Other
symptoms/issues:  I have noticed a bit of a rough idle but it is not
severe.   Also, when the outside temp is below about 60F, the car will
stall soon after a cold start.  There may also be a loss of mpg (still
checking this).

Questions:
1.  Is the back pressure transducer a part of the "egrc" circuit?  Can
the transducer be cleaned like the egr valve or must it be replaced?
2.  Where is the egr temperature sensor located?  Can it be tested
readily?
3.  Anything else that I should clean or check?