AUTO MECHANIC PROBLEMS (AGAIN)

[Durian Fiend]

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 would still look at all things ignition related for cylinder 1 first.  A bad O2 sensor should present with its own code. 

There should be a factory service manual online for this heap.  (Click and Clack descriptor  )   It would lead you through diagnostic tests for these codes.