Hyundai Accent revolutions for ITV

I have a Hyundai Accent that does not pass by the technical inspection because it is not stable at 2500 in emptiness (stopped the vehicle), or stays in 2000 or more than 3000 but among that revolutions it is not allowed to go up or down, some way to make it stabilize even if it is a bit for the review at least, I appreciate any advice, it is already proven with other pieces and does the same. accelerator, MAP, regime sensor, and other sensors.