Issues with my prius

Hello i lurked here for a bit and I was wondering if someone could give me some information. So I had the check engine light come on a while ago. I took it to jiffy lube and they did an engine tuneup replaced the 02 sensor and added another part. A couple months earlier me and a friend ran the scanner and all the error codes were emissions related we never saw anything related to the catalytic converter and there was no mention of this by the mechanics. A day after they preformed the work the check engine light came back on and after taking it into them they said that I need a new catalytic converter. I left their shop and had my friend run the scanner and now we can see an error code for the catalytic convertor. Any idea why we couldn't see this until after they performed work on the car?

I'm getting the struts replaced this Saturday and now I have the red triangle with the exclamation point on the dash and a red car with an exclamation point in the middle on the battery display. I read on here that this has something to do with the hybrid batter the guy i bought it from claimed to have replaced it and it looks like it's still working properly.