To be certain, you should:
* Consult your owner's manual: This is the best resource for the specific location on your vehicle's year and engine.
* Use a repair manual specific to your year and engine: This will have diagrams and detailed instructions.
* Search online for a picture of your specific engine: Searching "Chevy Corsica [engine size] PCV valve location" on Google Images can be helpful.
Without knowing the specific year and engine of your Corsica, providing a more precise location is impossible.