Don't need an o2 yet... Was just curious as to which brand is of better quality. Denso, or Bosch. RockAuto places both at roughly the same price.

Also, if you've changed your exhaust (manifold back), should you replace your o2 sensors?

 

My vote isnt for either listed, I'd (and did) go with NTK sensors, the price was good last time I checked from rock auto.

If you replaced all that on the exhaust system I'd say do the sensors as well ( thats also the easiest time ever to do so) unless you know the mileage on them.

 

Another vote for NTK. They are the OEM supplier of oxygen sensors for the XJ.

 

It could be as they age the fail to the rich side, a mileage issue. Just the act of screwing one out, then back in isn't a problem, just the anti seize. 60,000 mi? anyway I ran too long with mine dead..that cost me.

Seen different stuff for different years, but NTK always seems to be in there. No particular problem with Denso that I have noticed posted.

It MIGHT be some guys think there might be some issue with the Bosch for the earlier years. Generally they make good stuff in my opinion. At least the older stuff. (Like points and condensers)

 

I work @ denso, and doubt anybody can beat their quality..