So long story short, august I replaced ALL 02 sensors. Went off-roading, front one (upstream) had issues, finally fixed it. 750 miles later, downstream starts popping about 3 codes.. I do the same thing as upstream (clean it and the catalytic converter itself, which cleared 2/3 codes, the one not being cleared which is p1159), then swap the two downstream to see if it is the cat or not. I thought it ended up being the 02 sensor, ordered a new one. Put the new one on today, 13 miles later, check engine light comes back on. I get it scanned and there’s like 6 different codes, mainly being about an exhaust manifold leak going off. For reference, the codes I was having before replacement were bank 2 sensor 1(or 2), having to do with the lambda controller (off the top of my head P1173), this was the only code before replacement today still going. I decide to put the “old” 02 sensor back on (less than 5k miles), drove it around for approximately 25 miles, check engine light comes back on. Get it scanned, and the only two codes popping up are P0159 and P1159. P1559 was there earlier today, but the exhaust manifold leak and the other 500 million codes going off were gone. I am so confused at this point, and have no clue what is ACTUALLY the issue bc there’s so many different codes going off randomly. Please help. Thank you.