If you are relying on the Toyota oil pressure gauge to say it is low, that seems to be a standard Toyota problem with the gauge. Mine shows a little under half when cold and then drops down to just above 0 at idle when warm and has done so quite successfully for some time. If you really want to check the pressure, get a calibrated gauge or mechanic to hook up to it. As far as the ticking, who knows? Does it do it all the time, when warmed up, under load, ??? Is it an auto or manual?

1997 T-100 4X4 Xcab,Warn Hubs
02 Camry LE
2008 Yaris