2010 Toyota Tundra will not stay running

My 2010 Toyota Tundra will will start up and then shut right back off when hot or it is warm outside. In the mornings it runs just fine. If i can get the rpm up and able to hold it for couple of minutes then it will run fine. It does have a p0420 code which is "Catalyst System Efficiency Below Threshold (Bank 1)". I tried runnkng come catalytic converter in the fuel and it didn't make a difference. Just put a new battery in it this week after this started. Any advice will be greatly appreciated.

Thanks

 

How many miles are on the truck ?

 

About 250,000

 

I like to start with easy. Have you checked the electrical ground connections and made sure they're clean and making good clean contact?

 

Check the coolant sensor, since you do not have cold start issues
could be bad cat(or starting to fail) or 02 sensor, or leak somewhere in exhaust
I would check those things first.

 

more https://www.tundratalk.net/threads/p0420-engine-code.656057/

https://www.tundras.com/threads/o2-sensor-or-bad-cat.2674/

 

OP here are threads with that code so you can review. Is probably a bad 02 sensor. You may have other issues however and rodent damage to wiring is certainly a possibility.

https://www.google.com/search?q=tun...HTeVCpoQrQIoBHoECCsQBQ&biw=1600&bih=757&dpr=1

 

If it won't Idle, clean the MAF and IAC.

 

@Wolfmanr81 do you have any other codes, or just the 0420? My experience has been that if you have an oxygen sensor issue, you will get a code for that too. Otherwise IMO the sensors are doing their job and telling you what’s wrong. Obviously, it’s a good idea to verify the sensors and MAF.