Revisiting an old problem of mine.

I have a set of Berk HFC that I originally put on last year and the pre-cat driver's side sensor triggered. ONLY the driver's side pre-cat sensor is going off. I'd like to put them back on but I really don't want the stupid CEL/SEL to go off again

Long story short:

-Installed Berk HFC and pre-cat driver's side CEL/SES went off (P2A03 code)
-Looked for any crack/leaks in the cat where the OEM brace mounts, couldn't find anything and everything looks OK
-Only the driver's side cat is tripping a light. The passenger is perfectly fine apparently
-Took off the cats and replaced with OEM. All lights have been gone for months, since then, so the cause is definitely the cat itself

Looking for anyone with some advice on what could possible cause a pre-cat sensor to trip. From what I've read, it's just a AFR sensor so is it possible I just simply have a bad cat? A bad cat would trigger a post-cat sensor light though...?

Ever since reinstalling my OEM cats, the CEL went away, so it seems the sensor is working fine so I don't think replacing it will do anything.

The only thing I can think of is that when I originally installed the cats, I was missing the correct gaskets so maybe it's a bad install? My mechanic used silicone to seal the connection between the header/cat. Is that even a possibility?

Thanks!

 

Could be a leak, I'd try with new gaskets from Z1. If it comes back on, get an 02 bung extender and you should be fine. Or a tune. Tuner can turn off the warning.

 

Thanks for the reply!

Would a bung extender work on a pre-cat sensor? If I remember correctly, it's a total pain to access the o2 sensor on the header.

Looked up some gaskets and they're about $100 shipped to Canada

My mechanic says gaskets won't help but hearing a lot of recommendations for gaskets.