P0420

hello just looking for some help. The code p0420 came on on my truck got a new converter was install and the same code is popping up. Can someone tell me if something else can be the cause of this my mechanic has clean everything and code still coming on. I have a Toyota Tacoma 2009 4cylinder 2w drive

 

Just goes to show quickly replacing parts isn't the right solution. There will be more come along quickly to tell you what else you should replace without troubleshooting.

You need to do some more troubleshooting to get down to the root of the problem.

Here are some search results to start reading through.
https://www.tacomaworld.com/customsearch/?q=P0420

 

Could it be that there is a leak??