P0430 Failed Cat - Confirmed?

[JFP in PA]

The three way cats in these cars are excellent. We have had customers go 200K miles and more without problems. Many times, premature cat issues can be traced to gas quality, and/or aftermarket "tunes".

[Vtx531]

Do you agree the cat is bad? Or is there more diagnosis I need to do with O2 sensors?

Also, I am confused now because I thought the cat that would need to be replaced is the one that is combined with the manifold. Going to buy them off another member on here today but reading another post was saying the threeway cat is the bigger one further downstream? I thought the cat that is the one closer to the muffler end is unmonitored?

[JFP in PA]

Originally Posted by Vtx531

Do you agree the cat is bad? Or is there more diagnosis I need to do with O2 sensors?

Also, I am confused now because I thought the cat that would need to be replaced is the one that is combined with the manifold. Going to buy them off another member on here today but reading another post was saying the threeway cat is the bigger one further downstream? I thought the cat that is the one closer to the muffler end is unmonitored?

Sensors can be checked by testing voltage and continuity.

What year and model is the car?

[Vtx531]

2001 boxster 2.7

I read another one of your posts saying the bolts are almost guaranteed to snap off from the exhaust header - now you’ve got me thinking I should just leave it alone and ignore the CEL

[pilot4fn]

Now I got woried... I have same kind of header change ahead in a couple of weeks, but am now concerned why the bolts would almost guaranteed to snap...

Originally Posted by Vtx531

2001 boxster 2.7

I read another one of your posts saying the bolts are almost guaranteed to snap off from the exhaust header - now you’ve got me thinking I should just leave it alone and ignore the CEL