Have been getting both 0304 (KS) and 0503 (front rt O2) for a few months now - both codes thrown at the same time maybe once every 1K miles or so. Max has 111K on the odo so its not too surprising they're failing.

Checked the FAQs, performed the resistance test on the KS - that's hosed for sure. O2 diagnostics are inconclusive but I have continuity (no harness pbm) so I figure the sensor is bad and given its age, it's no biggie to pop in a new one. Plus, mileage has been steadily creeping downward from 24 to just over 20 mpg so all things seem to be pointing to these two. Sound reasonable?

Ordered both parts off internet, one from JRN (KS @ $109 shipping incl) and one from Conicelli (O2 @ $107) so while not the lowest prices, they are significantly lower than the $175 and $215 prices (respectively) quoted by my local Nissan Stealership

Seemed like the right thing to do and this way I can buy the new tools I want, ahem, *need* and not feel guilty

Will post back after I complete the installs - should be a hoot in the unheated garage...

tofor

 

For the KS, get a socket wrench, a 10" extension, a universal joint, and a 12mm socket. It'll take a little work, but the bolt will get loose, and you should know what to do from there. Anyways, I'm not sure about the O2 sensor, so free bump.

Oh, and I wouldn't worry about the cold. Up in CT, my hands got numb, and so did my face, but it couldn't faze me.