K&N oil fouled my O2 sensor

[jonatj]

I was a dummy and over oiled my K&N air filter. Not only did I forget to let it dry thoroughly, but I oiled both sides. *sigh*. Now the check engine light is on and odb2 scanner says P0420: Catalyst System Efficiency → Below Threshold → Bank 1.
Okay after a well deserved laugh at my expense, would anyone have a practical suggestion to clean or replace my O2 sensor? It’s a 2017 TSI so no MAF sensor on the intake to clean. Would it be worth trying CatClean?

EDIT: The engine feels fine and there’s no hesitation or other symptoms.

 

[Louiekaps]

In all my years as a tech I have never seen that code be from anything but a failed catalyst.

 

[TwinDad]

K&N oil will not do this.

 

[TwinDad]

Are you running a downpipe?

 

[aaronc7]

Yeah no

 

[jonatj]

No down pipe, the only mods are the K&N and JB4. So bad Cat is most likely? Yikes sounds expensive. Anyway to confirm somehow? I’m just out of the 3yr warranty.

 

[TwinDad]

Just get a downpipe and enjoy the jb4 that much more. However, I've never heard of a bad cat on these cars. My guess is the O2 sensor

 

[jimlloyd40]

No down pipe, the only mods are the K&N and JB4. So bad Cat is most likely? Yikes sounds expensive. Anyway to confirm somehow? I’m just out of the 3yr warranty.

Did you clear the code?

 

[GTI Jake]

Warranty doesn’t cover stuff you damaged anyway, but powertrain warranty is 6/60k in the USA

I’m with everyone else on either upgrade to a Catted aftermarket downpipe or snag a new to you OEM one for $50-100. They’re dirt cheap used because there’s a million out there and very little market for them.

 

[George Ab]

Did you clear the code?

This. Clear the code and then report back.

 

[jonatj]

I’m liking the down pipe idea a lot, but the Code cleared after using CatClean. I’m kinda amazed actually. When the check engine light first came on, I checked the code and tried to clear it, hoping it was a fluke. However it didn’t go away. I pulled out my air filter to inspect it and there was oil coating the bottom of the air box. I wipe that all up and let the filter dry out. Then poured in the CatClean and took her for a spirited 50 mile drive. Go to the gas station to fill up and cleared the code and started up without the check engine light and no codes. At least now instead of spending money on a replacement Catalytic Converter I can save for a CTS downpipe! Thanks to everyone for the quick replies!

 

[tigeo]

I'm not believing you could over-oil it that much or that even if it was coming off that it would cause any issues. How in the world is that even possible...to over oil it so much oil that there is oil all over the air box? Wow. Glad it got sorted for you!

 

[George Ab]

My money is on the Catclean did nothing to clear the code, but driving 50 miles and clearing code did. Glad you got it sorted.

 

[Diggs24]

Probably coated map or put sensor and freaked the jb4 out. You should clean those.

 

[Diggs24]

BTW, the correct filter is an AFE dry. No oil to mess with.