Secondary O2 sensor periodic check engine light. (12B701) Help Please

[pdxmkv]

I need some help on this check engine light code. This code (12B701) pops up the check engine light ever month after clearing it.

I don't know what would cause the CEL to be periodic.

I have changed the secondary o2 sensory twice now.

This code has only popped up after I changed my downpipe.

I have a ETS catted downpipe. ( Been on the car for 1 year).

Has anybody else ran into this problem?

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[BigRon]

Sounds like a problem with the Downpipe.
Usually catless Downpipes are throwing these types of errors.
I’m not a professional but I’ve seen a few videos on YouTube and posts from people complaining about these types of errors with aftermarket downpipes.

Do you have a strong exhaust smell when the engine is at operating temperature?

 

[zrk]

What cat is in your downpipe? It's probably just that.

 

[kaj]

I'd blame the cat on the DP. Swap the OEM part back on and see if it stops.

 

[pdxmkv]

Thanks everybody for the input, I was thinking its the DP as well.

I will try swapping out the DP to stock and see if the periodic CEL goes away.

As for the Cat for the DP, its a GESI Cat. Don't remember the actual model number.

 

[pdxmkv]

Update. Swapped to OEM DP.

No more code.

Found that the ETS downpipe had some wire that was contacting the tip of O2 sensor.

I don't remember seeing that during the first install

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