[m3_blanc]

Running MAD Catless downpipes, Full Titanium Valvetronic Exhaust NEL.

Have the big daddies mini cats 02 Spacers installed too.

Had a cel once months ago and it came off after a day or so. Got another cel now, threw 9 codes. Was able to remove 5 of em. But the rest that remain are stating

P0050 H02s heater control circuit
Bank2 sensor 1

P0050 H02s heater control circuit
Bank2 sensor 2
Etc.

Looked this up, usually just a fuse to remove on older models... Found some diagrams for G8X but not finding the right fuse location?

Anyone else seen this and know which fuse to check? I also ordered new mini Cats in case.

[SwankPeRFection]

Heater control circuits errors are usually a bad sensor itself unless it’s a problem harness or wiring wise beyond the sensor. Considering your errors are on the same bank and with both the wideband primary and secondary, it’s either two bad sensors for some physical reason (maybe they bank ran super hot and caused a failure of both sensors) or you’ve got a wiring issue on that side effecting both sensors. I wouldn’t drive hard with a primary wideband sensor having issues, even if it’s just the heater on it. Generally the ECU will flip to a safe fueling table for that bank since it can’t trust the feedback from that sensor any more.

[m3_blanc]

Originally Posted by SwankPeRFection

Heater control circuits errors are usually a bad sensor itself unless it’s a problem harness or wiring wise beyond the sensor. Considering your errors are on the same bank and with both the wideband primary and secondary, it’s either two bad sensors for some physical reason (maybe they bank ran super hot and caused a failure of both sensors) or you’ve got a wiring issue on that side effecting both sensors. I wouldn’t drive hard with a primary wideband sensor having issues, even if it’s just the heater on it. Generally the ECU will flip to a safe fueling table for that bank since it can’t trust the feedback from that sensor any more.

Thank you! going to replace both O2s for bank2.

FYI OEM:
Bank 1 Upstream 11-78-8-689-862
Bank 1 downstream 11-78-8-689-863

Bank 2 upstream is 11-78-9-454-704
Bank 2 downstream is 11-78-9-502-09

[m3_blanc]

The Bank2 O2 downstream wire was exposed due to being close to high heat, and caused the issue. The CEL wouldn't go away, after trying to clear and do battery disconnect/mileage drive cycle and the drive cycle where you cold start > drive 3mins 20-30 > drive 15mins 40-60 > idle.

Further inspection, it was the integrated supply module ZII that needed replacing, PN: 12 63 8638552.The fuse was out, and the whole module where it's housed needed to be replaced.
We'll see how this goes