I have a 2002 civic si with the stock k20a3, I started to get a bucking/hesitation when the engine is under load while under 3k rpm. There are no codes whatsoever so I borrowed my co-workers obd2 scanner that shows live data.

short term fuel trim drops to -12 whenever the misfires start, will have upwards of 60 misfires in one occurrence. All sensors seemed to be operating as expected until I saw the bank 2 o2 sensor voltage is dropping to 0 for very short moments of time, maybe a half a second or less. Bank one stays normal reading slightly rich when bank 2 reads crazy lean.

It’s leading me to believe bank 2 sensor is about to die, but I wanted to make sure there are no other possibilities before I start throwing parts at it as I have a history of buying everything I don’t need first 💀

Any help would be greatly appreciated.