1990 LS400 - intermittent stalling
 

Have intermittent problem - car is warm - generally driven 20-30 minutes - generally warm/hot weather - will begin to stall - erratic stall/surge - unresponsive to throttle for few seconds - shutting off and cooling down will allow return to normal operations. Lexus dealer replaced O2 sensors but problem returns - intermittently. Someone suggested catlytic converter could be instigator: heat up causes collapse/restriction in cat and exhaust becomes restricted. When problem occurs the car feels starved for fuel/air - choking. Anyone ever had similar?

I think you need to check the coolant levels of your car.if they are ok then check the engine oil because its also can be a reason for that problem that may be the oil is become junk and it warm your engine body.or may be its due to the hot weather. If its overheated more then the normal routine then I suggest you to install a exhaust fan in the hood of your drive.

I suggest you to install a exhaust fan in the hood of your drive.