New problem with my 2019 Elantra

I just got my camshaft replaced due to the issues in a previous post which ended up costing around $4000 and now not even a week later after getting it fixed my check engine light comes back on with a new code (in the image) I've gone from 32 mpg on the highway to now 20 mpg while barely keeping up with the speed limit does anyone know what could cause this and at what point do I get a Lawyer and get my money back under lemon laws because I've had issues with this car ever since I bought it and I've always gone to Hyundai dealers and at this point if I keep having problems it would've been cheaper to just get a brand new car.

I just got my camshaft replaced due to the issues in a previous post which ended up costing around $4000 and now not even a week later after getting it fixed my check engine light comes back on with a new code (in the image) I've gone from 32 mpg on the highway to now 20 mpg while barely keeping up with the speed limit does anyone know what could cause this and at what point do I get a Lawyer and get my money back under lemon laws because I've had issues with this car ever since I bought it and I've always gone to Hyundai dealers and at this point if I keep having problems it would've been cheaper to just get a brand new car.