OK, so I've installed HFC's a few months back and have gotten a CEL for Bank 1 Sensor 2, I replaced it and it was fine, for a bit, but then kept going on and off every couple of days. I replaced that sensor and noticed the splice wasn't good on it. Everything is fine for a few days and then the CEL comes on again. I get the car scanned and it's reading codes P0139, P0137 and P2A03.

The car is very hesitant taking from a stop and when I punch it in higher gears, like it stutters and then catches up. Every couple of days it reeks of fuel in the cabin. It's like the car is running rich, but have no issues with idle besides slight spudders every once in a while. I've look around the bay and see no fluids. I've sprayed around with carb cleaner looking for any vacuum leaks and looked for exhaust leaks around the cats.

I'm stumped with this one. Any else I could be missing. I was thinking of replacing the fuel damper and pcv valve, but I don't see them throwing those codes.

Note: When I rev in idle, I can hear a consistent hissing around 2000-2300 rpms, that's also the same rpms when decelerating that is pauses and then continues to drop.