Been feeling some hesitation in acceleration at times. I have a service record from Mazda from about a year ago that noted high cat temps but not to high to worry yet. I have to replace my down stream o2 sensor and figure now was as good a time as any to visually inspect. There's no rattle when I tap it but there's also zero light getting through. I mean no light at all. Any feed back would be appreciated.

 

It's probably clogged if you can't see light through it.
I would think it would have had a CEL if it was, but I'm not sure .

 

No cel from the cat yet. But yea, when I hold it up and point the back at the sun, there's no light coming through at all.

 

Have you tried shining a flash light through the front and looking down into it from the o2 sensor hole? That was one way I found mine was clogged along with a cel and loss of power. Its alittle hard to see any light coming through but if u havent recieved any cels it could be something else. If anything u can try driving it hard one night and seeing if it maybe glowing.

 

Looking at it is not the proper way to test it.

 

Then please inform the OP of your method since he is asking for help.
Mine was obviously bad with a CEL previous to removing it.

 

checked through the oxygen sensor hole and can see the flashlight through there. After browsing a few other threads I think maybe something else is the issue and my cat is probably fine.

 

Well my way is to just get rid of it, The other way is to remove it and shake it and listen for cat material rattling around inside. The right way is to have a cat efficiency test done at the dealer or qualified shop.

 

Hesitation and power loss have many causes. Could be anything from a spark plug to as simple as a stopped up air filter, search around on the forums and try some trouble shooting.

 

And 9krpmrx8 has a good point I changed mine to a topspeed catless so no worries

 

Thanks. I didn't know there is an actual efficiency test that can be done.
I have seen different methods through the years involving measuring heat before and behind and backpressure gauges.
Mine wasn't rattling even though the entire front half was reduced to the size of an egg.

 

Yeah the temp test is part of what they call the efficiency test IIRC.