NoobKim

I just replaced a used OEM cat yesterday but CEL hasn't gone yet. Is it normal?

Do I need to go to a dealer to remove it or it will remove soon?

outeiroj

it will go off on its own in a couple of days as long as its a good cat

B serious

Reset it by un-doing the negative battery terminal.

You'll need to put in your radio code and reprogram your radio presets.

If it turns back on after the reset, you still have an issue.

Or wait a few days of normal driving.

Car Analogy

Or buy a code reader (from say, harbor freight), or a bluetooth one that uses an app on your phone for cheaper. Reset the code on your own.

Useful to have.