AUTO MECHANIC PROBLEMS (AGAIN)

[HiloJulie]

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 am pretty sure that regardless of V6 or V8, you have Bank 1 and Bank 2 - Bank 2 being the other side of the engine.

Is this by chance a "Flex Fuel" type vehicle?

A common problem with the Flex Fuel Chevy ECM's was they get whacky over time and think you are trying to run 40, 50 even 75% alcohol.

You might try to reset the entire ECM by disconnecting the battery - negative off first, then positive and let it sit for 30 minutes.

Reconnect, positive first then negative and restart and let idle for 10 mins or so to relearn itself.

If no change, I agree on the oxygen sensor suggestion - or it could be a leaky fuel injector.