Did a search and didn't find info.

My exhaust note suddenly got quieter. Almost seems to wheeze a little. Also seems a tad down on power. Check engine light NOT on, no other warnings of any kind.
2.2 auto with 160,000 miles.
I'm wondering if the cat is clogged or choked.

 

It is very possible, especially if there is a possible coolant leak into the combustion chambers, antifreeze will clog up your catalytic converter

 

IF the cat is clogged you would get a P0420 code(period). It's the law.

I would however look at the flex pipe, if the sound has changed.

 

Cool, thanks. It's kind of what I thought. I was a bit surprised I didn't get the code warning. I'll have get a closer look.

 

You can just replace the flex pipe or the complete pipe and cat assembly