JPI EGT probe failure typical signs

My #3 EGT usually works just fine but every once in a while it will
jump up to an unreasonable number or even just report "OPEN PROBE" on
the screen. It may do this for several minutes and then just come back
and work just fine. JPI says to first swap it with another (#1 EGT) and
see if its the probe. However, if I'm going to go out to the airport,
put on my grubbies, decowl the plane, etc and there is a say 60% chance
the problem is the probe, I'd rather just buy a new probe and try that
right away.

Does having the probe go on and off line during flight a typically
failure method for JPI EGT probes?

-Robert