2000 dakota 4x4 3.9l Just put on a new catalytic converter and check engine light comes on now. Error code P0138: downstream oxygen sensor circuit high voltage left cylinder bank is the code I believe. What is the problem and how do I fix it? thx

 

That would be the oxygen sensor after the cat, it un-plugs from the harness, take out the old, put in the new, plug it back in, reset the computer and your done!

 

use a factory 02 sensor