do i have gearbox problem - used kia sportage 2005 (B) on 2005 Kia Sportage

when the car moves it does not does not change gear smoothly and off and on there is a "check engine" indicator on. Now it can only reverse easily but i find it difficult to engage the D gear. Do i have gear box problem or where can i get my gear box replace in Bandar Baru Bangi, Selangor, Malaysia? How much will it cost me?

Asked by for the 2005 Kia Sportage
you may need to change the air filer. i have this car and i have to change the air filter every month or it won't shift correctly . it sounds crazy, but its a problem, it will start hanging up in gears if the air filter is not perfectly clean