P0430 Catalyst Efficiency Below Threshold (Bank 2)
 

RE: 2005 Chrysler Sebring convertible, 2.7L-V6 with 111K miles.

I have already had both catalysts changed AND all four O2 (upstream and downstream) sensors changed and I am still getting the P0430 code. There are no exhaust leaks. I had this professionally done with OEM catalytic converters from Chrysler. However, the O2 sensors are aftermarket Bosch plug-compatible. I even swapped the downstream O2 sensors. Still getting the code. This is maddening! :mad: (Note: All four oxygen sensors are the same part number.) The repair shop manager stated that I needed to get OEM oxygen sensors because they are "tuned" for the Chrysler. Does that statement have any merit? Why would it be only bank 2 to throw the trouble code and not bank 1?

The engine is performing well. Fuel economy is also good (getting 23-30 MPG - EPA rated 21-28). Not burning oil. No soot or carbon in the exhaust pipe. All is normal for a four year old vehicle - except for the PCM (power-train control module) activating the MIL!

Still having the problem... does anyone have a comment, suggestion or anything to say about a P0430 code when the catalyst has been replaced?

O2 sensor circuits are very sensitive to conductivity problems because they deal in very low voltages. It may be worthwhile to go through each circuit on the affected side carefully with an ohmmeter to see if there are any anomalies there compared to the other side. Clean each connector with contact cleaner too.
It can't hurt and might help.

Thanks for the suggestion; will try that when I get a chance. However, a follow up question to that: I was told that the after-market (Bosch plug compatible) O2 sensors may not be "tuned" for the Chrysler - that I should install OEM sensors. Would there be any validity with that statement?

I put a cheap sensor in my Mercury Sable, and it worked ok for a few months. Then it started throwing codes again, so I replaced it with a Bosch sensor. No problems since. I don't know if that helps.