P2096 - DOWNSTREAM FUEL TRIM SYSTEM 1 LEAN
P2098 - DOWNSTREAM FUEL TRIM SYSTEM 2 LEAN
Set Condition:
The Downstream O2 Sensor is considered to be protected from extreme environments by the catalytic converter. The Powertrain Control Module (PCM) monitors the Downstream O2 Sensor feedback signal (called downstream fuel trim) to detect any shift in the Upstream O2 Sensor.
Possible Causes:
This diagnostic can fail when the O2 Sensor becomes biased from an exhaust leak, O2 Sensor contamination, O2 sensor wiring/connectors, or fuel contamination.
Check for any exhaust leaks that may have developed, check upstream/downstream O2 sensors for any wiring/connector problems and contamination (corrosion, oil/coolant, etc ...)
What's the quality of the fuel you're using? The Top Tier brands are identified in the link below.
How long ago did you install the new O2 sensors and cats? The NTK sensors may have worked for awhile but may now be out of range for what the PCM is expecting. Best to use Mopar original parts when replacing any sensors.
Some of the cheap aftermarket cats are good for only six months to a year before they start causing DTCs (diagnostic trouble codes). Was there any service life given with the cats (e.g. 36K miles)?
http://www.toptiergas.com/licensedbrands/
.