Rear O2 Sensor - 04 RX8 - Mazda or Quality OEM?
 

Guys,

I've had a P0138 code come up a few times (high voltage on O2 sensor - rear/after catalytic). From what I've read this is 99% a sensor about to go bad.

In preparation I've been looking around at pricing. Mazda brand is like $220CDN from the dealer, I can get from Mazmart for probably $200 shipped. Or, places like RockAuto and so on carry Denso & Bosch sensors that are advertised as "exact" fit and I would believe are good quality given the brand for MUCH cheaper. Like $100CDN shipped from RockAuto.

Seeing as the RX8s are pretty finnicky with ignition & emission pieces, what has been the experience here with non-Mazda but good quality parts like Bosch & Denso?

Obviously I'd rather save the $100+ if I can.

Thanks
Ash

it's the same. but I forgot one of the brands mixed the sensors over and it doesn't work.

I use NGK on that and works fine. I think it was Denso ?

Just to clarify, what did you mean by "mixed the sensors over"? You mean you used one brand for one sensor and a different for another? I don't see how that would cause a problem as they are built to a standard no?

Now if you mixed the front sensor with the rear sensor, that would cause problems...