Idle Surge

Good evening I have 206 feline vehicles, I had the catalyst discharged before it, it was before it goes down between 900 and 1000 rpm when it is idle, it does not do it very often, sometimes it falls to 800, it does not adjust the brakes when the brake is pressed or the gear is released. or idling motor malfunction?

I have the same situation, but I said it was normal.

The flow meter may be scattering because the floor is empty, the same problem happened with my friend.