AUTO MECHANIC PROBLEMS (AGAIN)

[Punatang]

Finally got some error codes:  "System too rich Bank 1" and "Cylinder 1 misfire detected".

There's a long list that can make these codes appear together.  Any ideas on narrowing it down?  I recently changed the air filter, so can take that off the list.

(A quick search shows that only a V8 would have a bank 2.  This being a V6, no bank 2).

I had the same and solved it with a new oxygen sensor which was really easy to replace and cost about $40.