Anybody know the cause of these readings?
 

https://cimg7.ibsrv.net/gimg/blazerf...c976e72da3.png
https://cimg7.ibsrv.net/gimg/blazerf...78d9a23294.png

https://blazerforum.com/forum/tech-a...agnosis-26408/

Sorry but since the vehicle is in front of you (instead of us) you will have to do some work to diagnose. They aren't codes that simply identify a bad part.

Start with the lowest code first (P0101)

Yeah thanks for that.

Which way should I take that?

I read that as a kind appreciation for your thoughts, with some frustration at his blazer, not you. Green blazer red butt. I've been on both sides of that one brothers.

Exactly. I've done the research and it points to the cat. It's been rattling since I bought it last October, but ever since the temperature dropped to the 40s at night I've been getting the p0101 intermittently. And I have the "loss of power" syndrome as well.
I've seen the exhaust on eBay for $237 with free shipping. Seems like a good deal.
But first I should correct the cylinder 4 misfire issue, which probably contributed to the demise of the cat.
This is an 02 2dr rwd, btw. 211k.

absolutely. Replacing the cat will not fix the underlying cause of it's failure.

I'm going to purchase the exhaust and the spider assembly and do both the following weekend after they arrive.
Any suggestions on what else may need attention while I'm working in these seldom seen areas?

I would definitely check out the reasons for P0101 and P0155 codes.

I have 3 new o2 sensors on stanby for tje p0155.
The p0101 is a mass airflow code, and according to what I've researched on here I'm thinking it's being caused by the cat as none of the other possibilities pan out.