my car is burning too much oil, I topped it up last week and the engine light has come up with the code p0420

What is your question?

last week my car stalled on the highway and it started back again but since then a weird noise is coming out of my engine and you can smell the oil burning. I got a check engine light with the code p0420 right after that incident. my cars performance is very poor car won't go over 100 km/hr. I just have 123902 km on the car. so after a day or two, I checked the oil in the car and there was nothing in there, although I changed the oil just two weeks ago so I topped it off but again today out of curiosity I checked the oil level and no oil in there again.

How long has your 2017 Hyundai Accent had this problem?

A WEEK