I have a 1999 CK4 Lancer with a 4g63T setup in it.
The issue I'm having right now is while driving on the highway sometimes I'd get a loss in power and the check engine light would come on. If I turn the car off then back on again the check engine light goes away and the car functions as normal, this happens randomly at highway speeds.

 

If your check engine light is on, the ECU will have stored codes and freeze frame data associated. These are like clues.