I need some idea here

I got this CEL yesterday
Front A/F Sensor Circuit Range/Performance Bank 2 Sensor 1

wondering if it's only because of my mods or it's because something is broken ?!!

I put 2.5'' HF cats about 1 week ago, with an Y / mid pipe 3'' straight to a cut out
my other mods; nismo CAI, intake spacer and MREV2, but those it's been a while since

no I didn't got an reflash yet

thanks to all

 

forget to tell, I put foolers on both cats

 

you mean "fouler"?? , can you take a picture of the setup?