I have a 2001 Kia Sportage 4x4. I can not get it to go faster than 90 km/h but just getting it up to 60 km/h takes a long time, then even longer to get up to 90 km/h. It's revving a little higher than it normally does but not significantly higher. I tried putting it in 2nd to see if it would rev higher, it didn't but the check engine light went on. Any idea what the problem could be?

I would start by checking for a sticky brake. If one or more of the brakes are frozen, then your engine will have to work much harder to get up to speed. Raise the wheels one at a time off the ground and try to turn them. They should turn freely. Make sure the other wheels are chocked so the car does not roll away from you. Also make sure the emergency brake is not applied and the transmission is not in park.

The throttle body position sensor or the oxygen sensor/ mass air flow meter.. Any one of these will account for the problem.. this is aslo garanteed because of the check engine light however to be sure which one it is,, you will need to have a diagnostic done on the vehicle.. this can be done by any automechanic that has a code reader,, and all of them do... Once the proper sensor is determined a simple replace will fix the problem.. remind the mechanic to reset the error codes or the computer wont realize its a new sensor..