I have a 2002 is300 catless headers with k and n intake/filter, and throttle lock. i can’t seem to get running perfect. I had a code for bank 1 sensor 2. It’s been replaced before but I replaced it again and it is reading on my scanner. My upstream o2 sensors are reading ok but not great, jumping around a lot. however downstream is reading 0v and 0.1v. From what I understand that should affect fuel trim correct? My short fuel trim is about 7-14% for both bank one and two. Any thoughts and what might cause high fuel trim?

 

"catless headers"

You'll always get O2 codes for sensor 2s without cats unless you have spacers or simulator.

 

Downstream do not effect mixture. They are only to report emissions level.