djspecv

Hi all,

I'm getting a CEL and when reading the faults, this is what it shows.

P0036 - Oxygen sensor heater behind catalytic converter, bank 1 – electrical fault (Permanent)
P0036 - Oxygen sensor heater behind catalytic converter, bank 1 – electrical fault (Pending)

A few relevant details and notes:
2021 Carrera 4S
BMC air filters
Soul Sport Cats w/ O2 spacers
M-engineering stage 2 tune

I tried clearing the faults but it keeps coming back.

At first I thought the CEL had to do with the sport cats and asked M-engineering why the tune didn't clear the fault. They replied sayingThese are not the typical faults associated with running high flow cats or competition link pipes. You have a specific code for the bank1 o2 sensor heater. So there may be a sensor issue or wiring issue itself. I jacked the car to check if there was any obvious wires disconnected but as far as I could see from under the car, it looked ok. Now I couldn't really see everything because the wire disappeared into an area not easily visible. I removed the engine cover to look from the top but couldn't locate the wire. I thought maybe if I removed the rear tire and wheel well cover (where the air filters go) I would be able to see it but no luck.

Does anyone know exactly where that wire connects? Pictures would be nice or an explanation of what I have to remove to see it easily.

The other thing I was thinking is maybe a blown fuse. Anybody know which fuse in the panel controls the O2 sensor heater?

Any help would be appreciated. Thanks in advance!

4 Rings

If using M-Tuner to clear faults it will NOT clear permanent faults only pending faults (from my findings)

doing a re-flash of your tune and that will eliminate any permanent faults....IF the issue continues/comes back then you have something else.

reddsektor

In my case clearing with M-tuner did actually remove my recent permanent fault surprisingly. And it hasn't came back (been a couple of weeks so far).

But in most cases yes, flash back to Stock and then re-flash the tune. That will definitely clear permanent faults. And then drive a few cycles to see if the fault ever comes back before digging deeper into the car.

djspecv

Thanks for the replies. I don't think it's tune related as the fault showed up even when flashed back to stock. When I installed the sport cats, maybe I pulled too hard on the O2 sensor cable and disconnected it. But I have no idea where it's connected and how to get to it without removing a bunch of parts. Any help or guidance on that would be appreciated. And any info on which fuse is responsible for the os sensor heater would also be greatly appreciated.

Also can I confirm that bank one is drivers side? I was told it was but then read somewhere on RL that it's passenger side.

TheRally

Food for thought: You might need O2 spacers for the O2 senor. But, if M-Engineering is saying these aren't typical faults I'd assume they would have mentioned it.

djspecv

Thanks. The soul cats came with spacers. It's also only faulting on bank 1 so most likely something to do with wiring or fuse I'm guessing. Hoping to find someone who has experienced this and figured out a resolution that didn't require bringing to a shop.

stef@europipe

The O2 sensor is a heated sensor and has 4 wires. There are 2 wires for the O2 signal and 2 wires for the heating element.

One of the heating wires is probably pulled out of the connector. That can happen when you (over)twist the wires.

You have to remove the cat and get to the connector, then push the small wire(s) back into the connector.

We already had this same issue on 2 different 992 Carreras.

Good luck!

dixonk

I had this happen before and sent the car to the dealer. It turns out that I messed up the o2 wire at the connector. Perhaps too much tension and it unpinned itself possibly. Anyway the tech fixed the pins at the connector and the code went away. If you look under the car and follow the o2 wire up the engine there is a connector. Check that.

djspecv

🙏🙏🙏 Thank you so much! I will give it a go this weekend!

djspecv

Just to close the loop on this thread in case anyone else has the same issue and finds this post.
Thanks to @stef@europipe and @dixonk for the advice. This was exactly the issue. The 4 pin connector was only showing 3 pins as one of the wires got pulled, probably while over-twisting the O2 sensor wire. Getting the cats off is relatively easy but if you have big hands like mine, it's a bit tricky to get to the connector. After removing a few wires/connectors in the way, I was able to squeeze in there and remove the connector and then I was able to push the loose wire so the 4th pin was pushed back in for the connector. CEL gone.

Thanks to the RL community, you guys are awesome!