Engine stalls when making a left turn or if you floor it and kick in passing gear it’s like you shut off key.. let up sometimes it comes back in ... other times put in neutral and start it back up.... have replaced TPS... just have emission code

 

What is the code?

 

P0420. Had it for several months. Still getting 20 mpg

 

My thought process is always fix known problems first. You don’t know if they are related.