dan is right on the money.

bently manual has the dvm (voltmeter) specs for the oxygen sensor... you can easily test that sensor following the procedure.

in my experience, when you unplug the o2 sensor while testing... you'll get a code which will need to be cleared.

no biggie.

i say => pull all the plugs and take a look at their condition.

however, if you have yet to replace the fuel pressure regulator in your car, i would start there as a matter of "zero mile" maintenance.

for the injectors, you can also pull each connector (one at a time) and the idle should change.
--
(http://drevilspinazzz.ytmnd.com) 'Be who you are and say what you feel because those who matter don't mind and those who mind don't matter.' - Dr.Seuss