2015 LR4 SCV6 (GAS) --- If anyone has replaced the #1 Right Bank O2 sensor, does this one look correct? If you zoom in, it appears that the wire (white section) on this one may have been cut and then patched back together. Having an issue with code P0420-00 (Catalytic below efficiency). Only happens if I go highway speeds, so trying to look at other possibilities before a CAT replacement.

Has anyone replaced the right CAT in the drive/garage at home? Wondering how accessible the top bolt at the exhaust manifold is from under there. Doesn't look like it is readily accessible.

Indy shop told me the 0420 is almost always the CAT and rarely something else. But thinking if that O2 sensor wiring connection is iffy it may be intermittent.

 

O2 wire looks correct. You could try shotgunning all O2 sensors, as that has cured the problem in some cases in our experience.

12 or 13 mm bolts holing the cat to the exhaust manifold, use a U joint socket and long extension. I would suggest getting the car really hot to heat up the bolts or use and induction bolt heater.

Good luck!

 

Thank you. I was considering trying the O2 sensor replacement route. May go that route yet, but not too convinced as it appears they all work in the same way as the left bank sensors when watching them all on the iiD live data. Will see if I can get under there and feel everything (nuts/bolts/connectors/etc) while it's cold and then decide. Watching live data i noticed fuel trims were different, but dont know enough about those reading to determine if it's some other issue. This all started soon after dealership replaced both High Pressure fuel pumps (was running rich both banks), so I keep thinking (over thinking perhaps) that the Tech disturbed one of the plug wires, coils/wiring or something. But maybe the 'puter has it right and I just need to put a new CAT in it.

 

It would be strange for the o2 to get molested during high pressure pumps.

02s should be changed when changing the CAT, so no harm in trying them first.

I see you are in FL, plenty of 49 state legal cats out there for cheap. I’m in CA, cats are expensive here.

 

Thanks for the feedback. Shop confirmed this morning O2s are functioning, and feel it is a CAT issue. Will go with replacement CAT. They are looking for one other than the factory unit for me.