PO136 on a 2000 to 2003 Dodge Dakota (It may be true for other year Dakotas) means "Downstream oxygen sensor circuit problem (left cylinder bank)". This is the oxygen sensor that is located just past the catalytic converter on the driver's side and measures the oxygen level after the exhaust has passed through the catalytic converter. I
Trouble code P0136 means: O2 Circuit (Bank 1, Sensor 2)
Trouble code P0136 means: HO2S-12 (Bank 1 Sensor 2) Circuit Malfunction
Code 41 is for the alternator not charging properly.
Trouble code P0304 means:Cylinder 4 misfire detected
Diagnostic code 44 means: Battery temperature sensor voltage out of range.
Fault code 16 means: Loss of battery voltage.
Code 55 is end of message. That means the computer is finished showing codes.
code 54 means there is no signal from the pickup coil aka ( cam sensor ) to the pcm.
Trouble code P1494 means:Leak detection pump pressure switch or mechanical fault
charging system excess or lack of field current
Trouble code P0720 means:Output speed sensor circuit malfunction
P0420 : catalyst efficiency failure. You have a failed catalytic converter.