Progress! The car no longer seems to stall after a hot run. Plugs still look pretty clean, so I don't think I have a badly rich condition. Is this resistor a band-aid, or does it mean that the ECU/MAP adjustments are off? Is this a good long-term solution, or should I be changing the sensor (or something else)?

The idle on this car always seems to be a little lumpy. Is this normal for the D-Jet system?

Thanks, Steve for helping to diagnose this one! This car has had an eventful last couple of months, but I think that might be the subject of another topic.