v6 Running Rich

Would appreciate a little direction trying to sort this one out. Truck is a 2000 Prerunner 3.4. It smells like it's running pretty rich tailpipe has plenty soot and my gas mileage has gotten pretty bad over the last year. At first it was just throwing a P0420, now I'm also getting EVAP codes 0441 and 0450.

Can someone with a better understand of how the ECU works help me figure out where to start? I'm not sure whether these codes are related or not. What I got from some posts on here is that the 0420 code is just a CAT efficiency code but that the ECU is not talking to that downstream sensor and it would not be causing a rich condition.

I'm also confused as to what if anything the EVAP codes have to do with it. Seems like 0441 in particular can have a lot of causes but I'm not sure why it would give me a rich condition. Could I have a vacuum line leak which is letting air in and causing the ECU to dump more fuel to compensate?
MAF is maybe two years old and recently cleaned, filter looks good.

Is this unrelated to these codes and I'm looking in the wrong place?

No emissions inspections here so I don't really care about clearing the codes if they're not causing the problem.

Edit: Also other than the mpg truck runs great, if there's a loss of power it's gradual enough that I never noticed it