As others have properly pointed out, check your guage before entering panic mode. The best way is to temporarily install a known good mechanical guage.
If you do indeed have oil pressure very near zero at idle, the engine needs attention.
It is a very common and almost always incorrect assumption to blame it on the pump. If the pressure comes up to 3 when you gas it, the problem is almost certainly not the pump. Oil pressure decreases when the resistance to oil flow decreases. This is most always worn bearings; mains, rods and cam bearings. It's a sign of a worn engine.
The good news for you is that the pressure comes to three. Check the guage, and do it, of course, at idle when hot.
Best of luck,
'01 C Class, Six Speed
'84 Euro 240D, 533K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in