99 suburban

I have a 99 gmc suburban and the engine service soon lite came on. I read the code. The code was p0430 eff low. I replaced both down o2 sensors on the number 2 bank. Reset the code and its keeps on coming back . I used a friends snap on code sensor and in the troubleshooting section it said that mech have had bad catl converter cause this problem . Is there a simple way to verify this. Please help.

There is a way. You have to take the temp. of the cat at the front and the back. If the temp is higher in the front you are fine, but if it the other way around, then it is time to replace!
Jay

thanks Jay I will try that. Do you know what temp range i am looking for on the catyt

There will be a difference between the front and back. I am not able to say what the temp will be as there are many different factors to take in. If you results are as I said then you will know. Het if you go under there and it is glowing red then you have just found the problem.
Jay

I took the truck to the dealer in December. They replaced the whole cat coverter on both banks under warranty. I found out that they are warrentied 84 months or 80,000 miles. Thanks all for your help.