Time for new catalytic converter again?

[pikeandchester]

 I have a 2001 Buick Century, 3100 motor, with 130,000 miles. Twice in the last week I have gotten a p0420 code, no other codes.. I poked around on line and it sounds like the most common cause is a bad catalytic converter. I replaced the catalytic converter at roughly 80,000 miles, about three years ago, with a Walker brand. Got the intake manifold gasket replaced at 65,000 miles. My question is, do I just put a new one in or is there anything else I should look at first? Thank you for any responses and Merry Christmas.  

[Jeremy airjer W]

How much oil does it use?

What is the warranty on the walker?

[pikeandchester]

Doesn't use any oil. I will have to check on warranty (very good idea, thanks). To update, I cleared the code a second time and it hasn't popped back up yet, after 450 miles of driving this week. May not be much to do until the code comes back?  Thank you for the reply Jeremy.