So, sorry about all these questions, but I figured its best to ask everything in one thread...

Several months back I started having trouble with my car running too rich and stalling out. I replaced some of the PCV system and cleaned the rest. At this time I also replaced the front oxygen sensor with a universal Bosch. After this I started getting a P0442 code, and i have no idea where the leak is. Everything appears to be connected well, and I've replaced a few of the connectors/hoses that seemed old and possibly leaking, but no use. The code still showed up.

Then I went outta town for a few weeks and came back. First of all I found that I have a nice little pinhole in the radiator. I think this is unrelated as the car has 216k on it and as best I can tell, the radiators still the original. I've ordered a new and plan on replacing sometime this week after it arrives. The CEL light was on and I read the codes, now I have P0442 and P0455.

To fix these problems I replaced the black/white one-way valve that sits by the fan and links to the vacuum tree (maybe goes to EVAP canister?) because it was no longer one-way. I also replaced my gas cap.

I've reset the codes and have driven about 50 or so miles on it, and no codes. I don't think it will stay that much longer, I'll take it out tomorrow and put 30-40 miles on it to make sure it cycles. Hopefully I only see one of the two codes, maybe none.

I can look my laptop to the car and get live data. When I do my short term fuel trim appears to jump between 2% lean and 4% rich. The long term trim is approximately 10% which leads me to believe that somethings wrong. In the fuel system part is says Close loop - fault, which I've looked up to be that the Oxygen sensor is bad.

Any suggestions on what could be wrong, or where to look next?