Sounds like it could also be a vacuum leak.Sporadic rough idle at low rpm's. Will be idling nicely at an intersection or red light and then slowly begin not breathing well. Will get to a point where it almost dies. I've gotten into the habit of sliding into neutral and giving it a bit of gas to keep the idle a bit higher. I've changed my O2's, my spark plugs, my distributer and wires. Replaced the fuel filter and fuel pressure regulator. Troubleshot the EGR and fuel pump relay.
I cleaned the Mass Airflow Meter, which wasn't very dirty, and it ran perfect for 3 days with no CEL. I finally took it to the local Toyota dealership and they pointed at the mass air flow per the readings off of the multimeter master computer. I try to do as much as I can myself on my land cruiser. I've owned it for over 20 yrs and currently sitting at around 340,000 mi.
You said you redid PCV and grommet?
Vacuum hose is cheap as chips. Change all the vac hoses
Also change oil filter cap o-ring