hi, I got a Mitsubishi lancer 2002 es automatic trans, when It change gears the car make a lot of noise and deaccelerates for a second with high rpmand then it changes the gear, I notice that is hard for the car to change gears, its on 1,2,3 gear, but sometime it does this for a week and then stops doing it for months. I took my car to several mechanics and they don't know what it is, they said that it got something to do with the transmission but they are not sure. they plug in the computer but nothing show up, only that I need to change the catalytic but I don't think that is related. any help or advice would be welcome.
thanks
Pablo
P.S.
the car works fine at more than 40

 

My car used to do that. I had installed a aftermarket intake and it was jumpy when I floored it but it had to tighten the clamps around it . Maybe it's your intake ?

 

Or 02 sensor ?