2009 Hyundai Elantra "Pinging" noise

Hello,

I have this "pinging" noise under the car/hood. I believe it to be the catalytic converter. I was told by the dealership it is normal. I get that. However, it annoys me "big time." There must be some way to fix this, even if it means replacing the c.C. I don't like that my car pings like crazy once it reaches temp and for 10 mins. After I shut it off. It drives me nuts! This is the first car that has done this that I bought (unfortunately I did not hear it when I test drove the car). So whatever it is that made the other cars not do it I want to do to this car so it is quiet.

Everyone keep telling me "deal with it." I also realize most people would not care, but I just do. LOL! There must be something I can do about it. I have researched suggestions like upgrading the gas I use and replacing the catalytic converter. What do you suggest? I don't want a "ping crazy" car.

Thanks,
Paul L.