Frank Reynolds

I had a new catalytic converter put on with all 4 o2 sensors replaced at the end of Feb so it's still under warranty. Now I have the check engine light come on with this error code p0174 on Friday, system too lean on bank two. Are these connected or are these two separate things?

Also, not sure if this is connected also but the engine is "pinging" when I give it gas around 35-45 MPH.

I feel stupid asking this, but is the engine in my '96 Grand Marquis a "high compression" engine? I ask because I've been reading that high compression engines should use higher octane fuel and I've been using regular 87. I wonder if I switch to the higher octane, will the pinging go away?

Thanks for any help/advice.