o2 data OK? or off cus exhaust leak tiny?2010 impala 3.5

hey if anyone like to help that be awesome ill post a log from after I got the leak from new flex flange barley heard. just tiny buzz when realy on it. any way the car is a cali emissons car it had the 2 cat down pipe I replaced it with just 1 cat fedral pipe cus im in R.I but flnge had small leak at new flangeat the manifold and I keptgetting p0420 cateff low came back fast evry clear. then I squezzed it lil more and almost all gone leak but p0420 came back but was after few days driving not same day like before...So idk if I cali tune is stricter or what my options are just want log some good data so I can start messing around with it alil now that got HP! just want make sure she running right before aplay obvy. so any help /info would be great obvy new here lol but not to stupid lmao


i put my stock tune read also from 2010 impala lt 3.5L non-flex vin N with California emissions if any that matters.

the log was 20 min ride home but rightafter i had to clear the 420 dct that came on on that ride to there for first time in days fyi

thanks all.... matt

Any leak before or near the O2s is never good to have so fix that. 420 code is cat inefficiently which maybe coming from the fact you now have 1 cat vs 2. Fix the leak and turn off the 420 code.

If P0420 is the ONLY code coming up, that can be due to the leak, or a bad cat, or both.

Unfortunately without fixing the leak you won't be able to determine the reason for the code.

yea that's what I assumed ...thanks guys. hate not having lift anymore!lol