Question about front oxygen sensors

[bugeye_fever]

So, I know that the front oxygen sensor for the subie sends an afr reading to the ecu. Mine is seems to be bad, so in the course of replacing it I found these online: http://www.rockauto.com/catalog/raframecatalog.php part number 15537. My question is that if I use this sensor will I get accurate wideband readings when logging with my AP? That would negate the need for a separate wideband sensor/gauge right? Thanks and I appreciate all your help in advance!

Ray

 

[HolyCrapItsFast]

The OEM front O2 sensor in your car already is a wide band or pseudo wide band sensor and that one you list looks like it is just a replacement. Though the stock AFR sensor is wide band it is by no means the best and is only a wide band up to around 12:1 and anything outside that range and it becomes less accurate. This is generally true for any replacement as well.

Also the ECU has a limit around 11:1 so you will never know whether you are richer than that and if it did read higher I wouldn't trust it. It is not the same high speed wide bands that Bosch makes.

The AP is perfectly accurate to around 12:1 but much past that I wouldn't trust it. Plus it is not as fast as a standalone gauge and you might be missing important events that cause spikes in AFR.

 

[bugeye_fever]

Ok, thats what I needed to know. I figured it wasn't the best option, but I'm glad to hear some back up on it. I'll get all the right stuff for logging when I build up the motor in the spring, thanks!

 

[Td_d]

I can vouch for that - logging the stock AFR sensor side by side with an LC1, you can clearly see where the accuracy starts pulling apart. It cannot be relied upon - especially in terms of high load, WOT areas - to give you an example, you could be seeing 11.3 or thereabouts on the stocker, whilst the true AFR using a highspeed Bosch sensor is 12! 0.7AFR in critical areas will grenade the engine comfortably :lol:

 

[Vermont]

I can vouch for that - logging the stock AFR sensor side by side with an LC1, you can clearly see where the accuracy starts pulling apart. It cannot be relied upon - especially in terms of high load, WOT areas - to give you an example, you could be seeing 11.3 or thereabouts on the stocker, whilst the true AFR using a highspeed Bosch sensor is 12! 0.7AFR in critical areas will grenade the engine comfortably :lol:

I can also vouch for a wide band as well man. I recently had my front O2 go bad as well. Only way I was able to tell was my AEM Wide band was reading richer than shit, while the stock O2 read lean. The AEM UEGO is nice man. Only problem is the install for the logging output takes a little bit of wiring work. Also a big problem with the non-subaru O2's is the plugs sometimes wont match up. Before I bought mine I was reading all over NASIOC about how alot of places online do not have the right plugs on their O2. So you might have to wire it into the old plug and hope for the best. On the other hand a Subaru O2 is going to set you back a good $200 or more.

 

[bugeye_fever]

yeah, from advance the bosch was 216, found it on rockauto for 130. But I'll just put another Denso in it and keep the paperwork this time. both have 12 month warrenties.