Loss of power from time to time

My car runs normal when I drive but after going 30min or 20 miles it looses power, my acceleration doesn’t go above 3,000 rpm and i have to press on the gas to make it go up there. Plus it takes a while for it to get to 20mph and won’t go past 30mph. Although if I leave it alone for 40-1hour it goes back to its normal self as if nothing happened. Thought it still does the loss of power if I keep driving after a while. Can anyone give me advise?

Not knowing your model year or mileage, my guess is that it could be anything. It could be a problem with the automatic transmission (assuming that’s what it has), a loose electrical connection somewhere, a fuel delivery problem, or something related to the exhaust, such as a leaky exhaust manifold that is letting exhaust gasses get into the engine’s air intake.

Maybe if you provide more information, I or someone else might have better ideas.

Could be the fuel vapor recovery system is not working and the fuel pump is pulling against increasing vacuum. Try driving with a loose gas cap, temporarily, and see if it still happens.

Could be many things
First off year make model and mileage
First would be inspection of ignition system and close inspection of distributor
Check if spark plugs holes have oil in them
Next would be fuel filter, fuel pump gauge required
Then it’s possible plugged cat converter or ign coil or ignited

Is the check engine light on when this is happening?

Oh my bad I thought it automatically puts it my car info. It’s a 01 Honda Civic EX, 159k miles, auto.

I reposted the info down below, my bad