Replaced Cat now I have Code issues
 

The mesh at the end of the Cat tube developed a hole on my 2010 2.2 LS. The dealer wanted $1300 for a replacement. I did some research and some calls and ending up buying one from Royal Exhausts in Canada. They told me it would have no problem with emission in NJ. So I bought it. I was a perfect find and all was well for about two weeks when my O2 code starting showing up. I reset it but it only returns after going through it's diagnostic time. I did not change the O2 sensors and maybe I should. I have contacted Royal and I am waiting for a response.

Any comments, suggestions, criticisms?

:propeller:

What's the specific code number ? There are several codes related to catalytic conv. readings.

Could be you need to hit the highway for 30 straight minutes at highway speed to burn the outgassing off.

But, what codes?

It could also be a fault that caused the original failure. Cats don't just wear out anymore, they die because something killed them.

Might not be a catalytic converter code.

Actual code is need to help.

But since you swapped the O2's into the new assembly, it's possible you contaminated the tip.

The code was:
P0420
Catalyst System
Efficiency Below Threshold (Bank 1)

A code P0420 may mean that one or more of the following has happened: Leaded fuel was used where unleaded was called for (unlikely) A damaged or failed oxygen / O2 sensor Downstream oxygen sensor (HO2S) wiring damaged or connected improperly The engine coolant temperature sensor is not working properly Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe Failed or underperforming catalytic converter (likely) Retarded spark timing The oxygen sensors in front and behind the converter are repoCheck for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required. Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady). Inspect the downstream heated oxygen sensor, replace if necessary

Read more at: https://www.obd-codes.com/p0420
Copyright OBD-Codes.com

First thanks for the info. Next I have a couple of questions.
1. is there a differnce between the upstream and downstream sensor?
2. When you say "inspect the sensor" what exactly am I looking for other than the waveform?

Yes the sensors are different, the connections are physically different.
You can use your scanner to clear the codes , the P0420 code will not clear by itself even after a few drive cycles

Well, sometimes it will clear itself, if it is still pending it will.

I had a P0420 that I never did resolve permanently. New cat, new sensors, new gasket everywhere, new injectors cleared it for a week or 2, new EVAP components