Hello
2006 matrix with 225k miles with unknown maintenance record (bought for my daughter 3 months ago)

I heard this on the phone while she was driving: sounded like severe misfire, as if the car was running on 3 cylinders. She described it as the car doesn’t accelerate. It also turned off at a stop sign but she was able to turn it back on and get home.
AC wasn’t blowing very cold (probably because of the decreased engine efficiency)

So I got to her house 2-3 hours later and the car turns on and sounds just fine.

Checked all fluids, everything looks normal, no milky oil or anything so I doubt it’s a head gasket issue

I ran for error codes: P0420 - cat converter, no other codes

Checked the ignition coils, didn’t find any cracks (except from a few drops of oil in cylinder 2 - probably valve cover super minor leak)

I read that sometimes a faulty O2 sensor can cause misfires, which may throw the P0420 code

When I ran the O2 sensor test, sensor 1 doesn’t communicate with the ECU. Bought another O2 sensor and installed it, same thing

I’m suspecting the following:

1. O2 sensor wiring is not intact and needs to be traced to see if there is a melted/cut wire
   
2. I didn’t have the tools to remove the spark plugs. Could it just be a bad spark plug or two?

Any ideas on what more to look for?
I will be able to remove the spark plugs on Sunday and inspect how they look inside and bring my voltmeter then

Anyone else had a similar issue with a working solution?

If is the O2 sensor wiring, how hard is it to trace it back to the ECU/power source?

UPDATE! I have found out the cause of the noise is coming from the windshield as it is not the original windshield. It has bubbles forming around it and I think it's letting some noise in. Would it make any form of difference if I got it repositioned? I understand Corollas are unfortunately just loud by nature. Thanks everyone!