Very loud engine noise, weak motor power, check engine on

welcome!
any trouble lights?

 

Hybrid battery died. Exhaust smelled because you pummeled the engine trying to get the same power
You usually get except there’s no 200 volt battery in the trunk assisting. It’s a very weak little go kart without a healthy hybrid battery so when no hybrid battery participation you literally have to floor it everywhere you go. Once it throws all the codes on the dash it’s done.

Dead or dying hybrid battery is close to the number one post we see on this site.

Use the search forum selection at top of page and search

Hybrid battery

So you can see what other posters have done in your situation.

 

check engine light means there are trouble codes. take it to a dealer, or someone with a prius aware scanner.

 

It could be a stolen catalytic converter you'll know by checking bellow the car or decoding the engine light. You should expect a o2 sensor code if it's a converter issue

 

It possibly could be a stolen cat, but seeing as the OP has responded in over four years and only made three posts, I'm not sure how helpful this post is to the OP.