Hey guys,
I am new to the forum, but not new to working on cars, trucks, pickups, or equipment. I have an 07 Aura XR (3.6 LY7) that is killing me and I am looking for any input you may have.
The Aura had the motor (or chains and tensioners only maybe, before my ownership) replaced and it shows. The chains are tight and cleaner than most I have seen. The engine is quite clean inside too, valves look good (using a bore came to scope them from the top) and the oil always comes out looking good. So one day the car hiccups and starts rattling. I tore the top end apart and I see the cam has a ton of endplay, and there is a bulletin to put a nylon washer in behind the cam phaser (Exhaust cam, bank 2 [front of car]). This wasn't it. Turns out the brick in the cat fell apart and was rattling around. It was a cheap replacement, so I am assuming the previous owner had it go bad and a shop threw this on it. So I replaced the cat, button everything back up, put new (cheap) O2s in it, and started having P1174/P1175. So I put new OEM O2s in and admitted to myself that the cheap ones were a bad choice. A few days in, I have P1175 back on again, and that was months ago now. I can't shake the P1175 (which I believe is pointing at Bank 2 [Front of car] unless I am wrong on this.
The car sometimes seems a little sluggish, lacks midrange power, but otherwise it runs great even with the P1175 code always on it. I had a noisy Purge Valve and a code, replaced that.

So a thought hits me. I had the idea that I was getting unmetered air in through the Purge Valve somehow (didn't find any other vac leaks anywhere and something at the time pointed me to this), and there was a code correlated with the thought that I don't recall now, but the important part is if I unhook the power to the purge valve, I only get the P0443 code on, and the P1175 stays off.

So, my TL;DR question is:
What causes the P1175 code, and why does it go away when I unhook the Purge Valve? The canister is good, the lines and canister vent hold a vacuum when tested so no leaks.
(Another notable item is I recently started getting the hiccup/P0106 MAP sensor code, along with P0340 and P0341, but I am attributing that to a weak Cam Pos Sensor and those are on order.)
Timing chains are tight, car seems to run well, all the hard parts seem good, but I just can't ditch the P1175. Theres a mild exhaust leak on the firewall side at the manifold, but nothing pointing to any issues on that bank except the recent occasional CPS code.

I am ready to scrap this pile, but I feel like it owes me money yet lol any help in finding this P1175 code cause would be awesome.
Thanks