P0030 code is a HO2S (your heated Oxygen Sensor) might need to be replaced.
You have two - so one usually refers to Bank 0 (being the Upstream BEFORE catalyst)
But that does you no good if you run Diesel fuel - then the P0030 code is something else but is emissions.
Considering the age, either sensor or wiring to it is bad or needs to be inspected and ruled out - this "30 code" is a Generic response to any issue with the Oxygen Sensor.