P2272, P2270 codes & SES light

Lapua

2020 370z Nismo w/ Motordyne ART's, Stillen Gen 2 CAI, HKS CBE, tuned on EcuTek

Hi all,

I'm having some problems with constant SES light and secondary o2 sensor codes. Car only has 18k miles and SES light + codes have just recently popped up at around 15k. Drove the car on this setup for roughly 10k+ miles with no issues or SES at all.

Discovered a crack in my passenger-side ART pipe and had them warrantied and replaced but that didn't seem to fix the issue.

I understand that CEL/SES and o2 codes are highly likely when not having cats but what I'm having trouble understanding is why it didn't happen for the first 10k miles with the exact same setup. Also had the car checked but discovered no leaks or damages, etc.

Codes are P2270 & P2272 (post-cat o2 sensors system stuck lean) Only thing I can think of is that my o2's are torched but with so little miles it just seems unlikely. Is this a problem at all or just normal w/ test pipes? Just trying to find some insight before I go spending more money on this thing lol. Any and all help is appreciated, thanks!