salimshah

'95 SC400 with about 140k miles.

Strange observation is that after a not so short drive [30 mins plus] on hot days only when I put the transmission in Park, CEL lights up.
The engine rpms, on moving to park levels off at about 750 rpms without any bouncing around.
If I rev the engine past 2.5K (in park) the CEL goes off.
If and when I shut off the engine and turn the key to run, there is no CEL.
The vehicle starts fine, idles fine and no issue in driving.
If the ambient temp is say below 75 [cool day in central Texas] there is no CEL after driving.

I am lazy in checking the codes [my obdII reader cant be hooked up (excuse], at the same time there is no CEL when I turn the ignition to run.

extra: A while back I did notice the idle controller trying to bring down the idle below 750 and the engine almost stalled, but then recovered as the idle control adjusted. It seems it went too far then it adjusted in jerks and then tried to bring the idle down again. All this was not smooth ... healthy operation should have been very subtle.
I have not changed any caps in the controller.

Salim