My 07 accord has a p0420 code I used my 600 dollar autel to look at the live data and the car runs fine almost perfect but I noticed right away the b1 s2 o2 sensor voltage is 1.3 which is well to high am I correct in assuming this to be the cause of the po420 code not the cat itself.
P0420 is a low efficiency for the cat. That code is usually caused by a exhaust leak , bad O2 , failing catalytic converter. Since your looking at the o2 numbers and it a down stream that might be a default number. Most manufacturers use a default number since there is no actual data stream.
Hook up your scan tool and post the bank 1 and 2 number . Also what are your stft and LTFT. If your scan tool and car has the ability pull up that temps of that catalytic converter for the front and back.
