For oil and other specs please refer to the link on the thread "Dewan Lancer Manuals". You'll find quite a lot of useful material there. The owner's manual has an oil chart for using different grades in different temperature ranges.
For your other problems, the following are the likely culprits:
-Map sensor
-O2 sensor
-Ignition coils
-Spark plugs
-Fuel filter
-Fuel pump
-Dirty fuel tank
-Dirty injectors
You can find tests for all these things in the factory service manual. It's a big folder and all parts are hyperlinked so download them all in one folder before using. Also, there's a separate unlinked chapter for the CVT named "F1C1".