I've been chasing a P0430 code on my 2002 for a while. When is it really the converters that are the problem?

A little background first. Was getting a P0155 error so I replaced the Bank 2 Sensor 1. Then I started getting the P0430.

Doing my research I realized one of the common causes is an exhaust leak. What do you know my car had one, right at the flange before the second sensor. Fixed the leak, but still getting the error. Only now it seems to be triggering faster then before when I check the data when driving.

The car has no other issues, drives fine no hesitation no rough idle.

Any ideas other then replacing the cats?

Thanks for reading.

 

it's usually never the cats... if you found one leak and fixed it at the flange, then there may be another leak... maybe further down the y-pipe just before the 3rd cat... this happened to me... i changed out the flange gaskets, sealed the leak at the flange, but then once the heat shields on the y-pipe were removed, it was like swiss cheese... those pinhole leaks even past the O2 sensor can trip the code...

if you can't hear any leaks, you might need to have a smoke test...

 

I second this. I change all the gasket. Them, I change all sensors and eventually turned the Y pipe or mid pipe that had been clogger. The best thing I recommend to you is, take the car to a good muffler shop and have to checked your exhaust system to see can found out any leak or the muffer tech can check the third cat in the Y pipe, to know that is not really your problem with the third cat is not clogger. I hope that help

 

This was come out from my small cat Y pipe.