05 KJ Cat codes

[JustSumDad]

2005 V6 Canada exhaust question.
I thought these had three catalytic converters, the one I just looked at only had two. One for each bank then into Y direct to muffler...
The car is throwing codes but the CATs do appear to be working.
Jeep runs fine, IR temp read on the pipe just before and just after CAT's both sides are about 100 degrees higher downstream.
Codes pulled via Torque

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Any input on likely fix here?

The P420 developed after test drive, was not present until fully warmed up.
The P430 and PO132 were present all the time.

Thanx

 

[JustSumDad]

It was suggested on FB group that the upstream O2 may simply be the only issue. Causing rich condition that creates the secondary issue of the downstream codes.

I wonder on that theory as the upstream error PO132 is on bank 1 and when I first took codes the downstream error PO430 is a bank 2 error.
Bank 1 upstream PO420 developed while on test drive and showed on second run of pulling codes.

 

[JustSumDad]

Starting to think these codes are very common...
Abandon the 05 as it seems to have transmission issues as well, went to look at an 03 today...
exact same codes???

no dash light on this one tho.... and plenty of power... more than the 05 by maybe 20%

I think we are going to go for this one tho, then replace all O2 sensors and see how it goes.

Price and condition on this 2003 is outstanding!!

 

[DadOSix]

Starting to think these codes are very common...
Abandon the 05 as it seems to have transmission issues as well, went to look at an 03 today...
exact same codes???

no dash light on this one tho.... and plenty of power... more than the 05 by maybe 20%

I think we are going to go for this one tho, then replace all O2 sensors and see how it goes.

Price and condition on this 2003 is outstanding!!

If you do decide to do O2 sensors - start with just the upstream ones. Seems as they get the most work. Also, most gurus on here recommend the OEM sensors with NTK/NGK as acceptable.

If you are new to these old KJ’s, they are fraught with electrical gremlins. A - they are old and have brittle wiring. B - Grounds that have corroded (aluminum vs steel) still seem intact, but electrically they are not.

I say this because, you can chase codes and throw parts all week and still not find the issue.

With your code scanner, if you can do live data, look at the fuel trims - short term and long term. They have a wealth of data for deciphering which sensor (O2, needs addressed). On my 06 Kj, my son ran over a downed tree limb that looked small enough. But it was big enough to stick up under the jeep and tear the downstream sensor line off, which threw a code after a week or so.