Hey guys,

So I've narrowed mine problem from the previous thread (here) down to most likely a lazy or slow front O2 sensor (Bad mileage, hesitation at low rpm and low throttle).

Now, I know OEM is probably my best bet but given that the Bosch is $150-200 cheaper for a front O2 sensor, I though I'd give it a try.
I've searched for an answer and I found a couple threads(here and here) but it seems like the question was never answered.

The problem is that the bosch part number for the upstream o2 sensor (front) is the same for the downstream o2 sensor (rear): Part #15042. Of course this is for the auto.

Several online stores have these for sale but some say its for the front, others say its for the rear, or both.

So am I safe to assume that this particular sensor is compatible to replace both the front and rear O2 sensor? Or does it seem like a part number error?
I'm probably going to contact Bosch for a definitive answer but they seem to only take phone calls so I'll call them tomorrow morning. If any members here have had any input, it'll be greatly appreciated.

 

You need to get OEM (which I beleive is NTK). The upstream/downstream sensors are not the same--one is wideband and one is narrowband. I just had to replace my upstream 02, and the cheapest place I found was amazon.
#25673 is upstream
#22506 is downstream

 

I understand that the front sensor is wideband heated and the rear sensor is narrowband.
After a bit more research, it seems that the Bosch 15043 is a narrow-band sensor and should only work as a rear o2 sensor.

Is it correct to assume the NTK (NGK) sensors you linked work for auto rx8's as well?

 

Seems like the more I research about different o2 sensors, the more confusing it gets.
I've looked at brands like Denso, Walker, Bosch, NTK, etc.

Seems like some companies have different sensors for automatic and manual trans, front and rear. But then other companies say the same sensor works for auto/manual, front and rear...

Right now, I'm trying to look for one that specifically says "wide-band, heated, auto, front (pre-cat, in exhaust manifold)."
Or is there something I should look for instead (length of cable?)

 

having handled both, i cannot tell any difference between the automatic and manuals sensors (needed to replace my sensors on my 04 automatic, replaced them with sensors "for a manual" and they work perfect). HOWEVER front and rear sensors are (obviously) different and try to stick with the same brand for front and rear sensors
Goodluck

 

So which one is the right Bosch rear Narrowband O2 sensor for Automatic RX-8 2007? I have a P0420 code and I want to change that first before trying the catalytic.

seems like the Bosch are cheaper??

 

P0420 is catalytic, dont waste your money on the sensor.