My car's check engine light is on and now there's a weird rattling noise
That sounds serious a check engine light plus a rattling is not something to ignore you should get it scanned soon
If the noise is from the front end it could be a loose heat shield or suspension part a quick diagnostic will tell you what needs fixing
In my experience a generic scanner code can be misleading so ask for a full diagnostic and avoid driving far until you know its safe
Best move is to book a shop you trust and have them check it under warranty or as needed and keep an eye on how the car drives