2001 Cadillac EL Dorado Hestiation/cuts out

There is a rev limiter that kicks in around 4000 rpm. Do you have a check engine light? Regardless, have it checked for codes, and when checking, also look in freeze frame. I am suspecting you have crank sensor faults, 2001 was prime for these. P0335, 336, 385 or 386 are some possibilities for indicating a need to replace. It could be possible that this fault is random, and intermittent enough that the code(s) get dumped out of history, but will lie in freeze frame and often go unnoticed.

I have seen others post that independent parts stores(autozone, pep boys, etc.) Will check codes for free. You can check them through the on-board feature by pressing and holding 'off' and the passenger warmer rocker switch on your climate panel. The segments will light and it will display codes. As I was saying, this will not give you access to freeze frame files, nor am I sure that the parts stores can access that file either. I am a dealer technician, and I know the GM scan tool can. It is worth checking first, to see if they are in code history.

If your racing in park gets up around 4000 rpm, then yes, it is the rev limiter.