Hesitation at 4k and over when warm

[Jojo]

Hi,

So I started my (cold) 2004 Boxster S without any issues, normal turn of the key and engine fired normally. If I foot the gas, the engine revs up to wherever I press up to full rev counter.

But once the engine starts to warm up, the engine will not rev up to more to approx 4-K revs and starts to hesitate if I keep trying to rev it up. Also noticed that once warm, the restarting of the engine takes a bit more turning than normal to start. I have not yet checked for any codes, but o lights came 'on' on the dashboard. Car is not used daily and has still only 25,000 miles on it.

I was think of plugs and coils, but not sure what else to look for.

Any input would be appreciated.

Thanks to all

Jojo