P0100, P0111 -- Red ECM Temp Warning & RTD Engine Stall

- Today at 5PM while heading home, I just got the red triangle of death (RTD) on a DTC reading of p0100, p0111; engine control module (ECM) also showed a blaring red car w a thermometer; VERY bad news indeed. Fortunately i was at a stoplight on a 35mph back road. I think i lost engine power as gas pedal didn't function during the incident; definitely quickly powered down and back on the engine and drove off with my hazards, real slow. I cannot fully recall as i was stressed w performance anxiety from onlookers. Felt like 30 minutes went by, but really 1-2 minutes; infact this one huge truck drove on the grass around both me and the car behind me. This was just 6 hours after fully clearing DTCs for my coolant job as of recent: p1118/p1150/p1121. ughhh; if its not one thing its another.

- A quick online peruse through the general Toyota DTCs explain that its more a Mass Air Flow (MAF) connection issue (p0100) and possible faulty intake air temp (IAT)/dirty filter (not-just swapped those out a month back) sensor (p0111). REF:
- P0100 =the mass air flow sensor has an open or short circuit.
- P0111 = Intake Air Temperature (IAT, Sensor 1) Circuit Range / Performance' Maybe the MAF sensor is dirty or broke? Have you cleaned it? Is it connected? Not so as i hi-pressure washed the heck out of that engine bay just yesterday.

- Quickly and gently I parked around the corner. Disconnected and extracted the air intake housing connecting the MAF sensor; cleaned the intake area with carburetor cleaner (saving the MAF sensor for home where i have the MAF cleaner), wrapped the car all up, unplugged the rear auxiliary battery for 1 minute to reset the dashboard lites.

- Drove home for 7 miles under 45mph; good no resurgence of the RTD. I performed a quick MAF clean, then reconnected wiring harness and wiped down the air intake housing unit that i removed. Now I'm off for a road-test to replicate that issue... more to follow.

 

OK back from a road test that took me for a round-a-bout and endless 100miles.
Hesitant at first i only kept it at highway speed of 55mph. But after mile 25, i took it up to +70mph. Handling and throttling is good as i just recently gave the Prius a front end alignment. I did feel some poss sputtering/misfiring on the back-end of the 100miles.

Coolant for engine and inverter is stable and oil dipstick is full and golden yellow. Engine efficiency is still ~ 45mpg highway.

Still cannot replicate the RTD earlier; puzzling.

Now i did let the car sit for the bulk of 7 months, leading up to last Christmas.

Note, I did add late 3ozs of Lucas upper cylinder lubricant after i fully filled the gas tank; didn't give the gas-Lucas solution time to mix. As of recent, I have been using this Lucas regularly, as i got the big bottle. Gas tank was at half when i got the recent RTD; now tank is 1/4 full.