2000 Dodge Caravan

First off, before you swiping the credit cards buying all these parts and paying someone to put them on, tell us what check engine codes that you get from the computer. You may not need to purchase all of the parts.

O2 sensor measures your exhaust gas mixture to make sure that no harmful gasses being emitted through your tailpipe. You, however, have 4 oxygen sensors: 2 in the exhaust manifolds, and two after the catalytic converters.

O2 sensor htr: Oxygen sensor heater. All of your O2 sensors have the built-in heater.

Catalyst: Catalytic converter transforms most of the harmful emission gasses into carbon dioxide and water vapor.