OT: Car stalls at idle when hot, and then won't start

[Thrift Store Scott]

billb wrote:
fuel flow
MAF or any number of sensors, though they should show up in codes
EGR ?

not so sure a filter would cause a stall at idle as fuel flow should be low then but filters do weird things

It sounds like the EGR (Exhaust Gas Recirculation) valve is sticking in the open position. When working properly, EGR valves are shut at idle and open at all other times. When one sticks open it will cause the car to run rougher and rougher at idle until it stalls, especially at red lights and especially on hot days.

EGR valves are usually actuated by manifold vacuum run through a thermal vacuum switch that only opens once the engine has reached operating temperature, so the first thing to check would be the condition of the associated vacuum lines. If the vacuum lines are okay, then replace the valve itself... they're usually only held on by two bolts and aren't expensive, although clearance and access can be a problem on some cars.