2001 Lexus RX 300 - Engine powers down after 60 MPH

Lexus 2001 RX300, deceleration over 60mph to 45 mph, with engine running rough, turning car off for ten minutes resets car to 60mph again

Please don’t take this the wrong way . . .

I’m having a hard time understanding what you just said

Car decelerates after reaching 60mph. It drives fine until then.

when it’s decelerating, is your foot still on the accelerator pedal?

is/was the check engine light on and/or flashing?

this could actually be engine- or transmission-related at this point

you’ll want somebody to hook up a scanner and at the very least retrieve any engine or transmission fault codes. Autozone might do this for free.

A friend said the “brain” is putting the engine into the “limp” mode. Not sure what to do about that.