Loss of Power, no CEL

[CDsDontBurn]

Current symptoms of my CG 2 are:

• Poor acceleration
• Little to no power being made above 3,500rpm
• Can floor it and RPMs won't get above 5k RPMs
• Will sit at high RPMs before shifting to next gear
• Rattly noise at higher RPMs (3,500+)

Like title says, there's no CEL present for anything out of the ordinary, IACV and random misfires, that I've been chasing for years.

I'm hoping that someone here can have some insight as to what might be my issue or at least where to start looking. A friend of mine suspects that it might be my catalytic converter, but not sure how to test this. I'd like a boroscope to look in there, but I don't want to spend the money to buy it for just this one thing. I guess I can unplug the O2 sensors, but that would trigger other issues so I'm not sure if it that would trigger a false negative?

Here's a video of this when issues first started. Performance degredation wasn't as big back then, but now it's terrible. My wife's Hyundai Tucson is better off the line than my v6 Accord .

 

[CDsDontBurn]

As I spread out my issues across different platforms, a few have suspected that it might be my catalytic converter. So to test that theory, I just unplugged the upstream O2 sensor right now, and it seems to have had positive results. The engine was able to spin up to 5k RPMs without issue.

Next up, CARB certified catalytic converter and new J-pipe because my OEM CAT was stolen years ago and they cut the flanges off of the J-pipe.