Diagnostic Trouble Code P0171 & P0421 What Should I DO ?

My 1996 Ford Probe with a 4-cylinder engine which is all stock came up with the diagnostic codes PO421, which is "Warm Up Catalyst Efficiency Below Threshold (Bank1)," and PO171, which is "System too Lean (Bank 1)." The vehicle has 130,000 miles on it.

The catalytic converter was changed on it at 95,000 miles.

What should I do to repair the car which has these codes? Auto Zone was the one that gave us these diagnostic codes and they did not know what parts on the car needed repaired.

Please advice.

phone a dealership and ask them, they should give you the problems for free