Kwiksen Oxygen O2 Sensor 234-4308 Upstream Replacement

This part is advertised as a correct fitment for upstream right. That is not the case. It is for downstream right or bank 2 sensor 1. On a G35 2004. The pictures I posted are for upstream or bank 1 sensor 1and 2Besides that it fit perfectly for downstream right.

I ordered these with 140k miles on my '03 350z. They work - along with a few other tune-up items, these will buy themselves back in fuel savings in just a few months. With no change in driving habits, I've gone from averaging 23, to 25 mpg.

these are not good 02 sensors.i had two fail in my Infiniti G35 and One fail in my impala.I replaced the two Kwiksend with Denso I purchased elsewhere and the impala runs 100 percent better now !