2001 Nissan Sentra Engine stalls after 28 seconds at idle

My Sentra 1.8 QG18DE Calif stalls at idle when warm, every 28 seconds. Restarts fine but goes back to struggling and dying about every 28 seconds. The engine usually avoids the stall (idle drops to 500 or evn 300 but recovers) for the first few minutes of warm idle but progresses to stalling at the 28 second interval. The car also has stalled out on the freeway under stop and go traffic conditions. Drives without any trouble otherwise. My scan tool shows that the Fuel System 1 and 2 both show an OL-Fault together on both 1 and 2 immediately before the stall. The fuel pressure checks out ok, and does increase slightly when the engine is trying not to stall. The spark advance also increases when trying to avoid the stall. Idle speed is within spec, except when trying not to stall at the 28 second interval; and ignition timimg by light is within spec.
The Nissan dealer tells me all factory recalls have been performed for the vehicle. I have replaced the crankshaft position sensor for no other reason than it was a component that could cause this trouble. I replaced the IACV - AAC valve because I lost a shim when checking it out and it was not happy without it. The throttle position sensor was not testing out (no closed signal when there should have been) and I have replaced and adjusted for correct switching. The codes that have come up once, but have not repeated after erasure have been P0140, P0160, and P0175. The HO2S front and rear check out with resistances at 3.4 and 3.5; and voltages that vary between 0.0v and 0.93v meeting the above 0.47v and below 0.43v criteria when revving above 4,000 rpm and releasing.
I just got done with a test drive after putting the ECM back in it's box and removing the pressure gauge from the fuel line. The car drove fine and did not die even at the stop lights that took more than 28 seconds. When I got it back in the driveway, and removed the load from the engine - put it in park and turned off lights - it would die. First Fuel System 1 would go OL-Fault, and then when System 2 would also go OL-Fault, about 3 seconds later the engine would stall. If the engine did falter but recover the OL-Faults would both clear in about 2 seconds after the falter.