Pesky oil pressure alarm problem on my '91 Carat turned out to be bad .9 bar
sender.  The alarm would come on only after 45 mins driving and then usually
only at 2100 rpms for a few seconds.
Checked the pressure with a manual guage at operating temperature and it was
fine.  I figured it must be something in the alarm system.
.9 bar switch is the one located on the oil pump.  Ran down to Sears and
bought a 24mm socket and adapter to go from 3/8" drive to 1/2" (they don't
sell 24mm in 3/8" drive).  Used my 3/8" breaker bar to break her loose and
then unloosened it the rest of the way with my fingers.  The 24mm socket from
Sears was just the right depth for the sender (not to deep and not too
shallow).  I loosened up the alternator belt and got it out of my way for this
job.  I don't know if it is a must but it was just one less thing in the way.
Drove 45 mins home and never a peep from the alarm.  Drove at 2100 rpms
repeatly and for prolonged periods trying to get the alarm to come on.
Nothing.
So that is the end of my saga.  Hope this helps anyone else having a similar
problem.
Ken Wilford
John 3:16