There should only be one.
One. If the van has dual exhaust, then two.
Catalytic converter efficiency failure.
There is one on each side of the catalytic converter.
In the exhaust pipe, just behind the engine.
There are two. One before and one after the catalytic converter behind the engine.
It's welded in like a muffler. Any muffler shop can do it for you.
No
It is the sensor behind or in the catalytic converter.
The 2002 Dodge Grand-Caravan has 12 valves.
The 2014 Dodge Grand-Caravan has a V6 engine.
The 2005 Dodge Grand-Caravan has 12 valves.
The 2013 Dodge Grand-Caravan has 24 valves.