O2 sensor differentiation, help please

[will_drift_4_food]

I have an S13 Blacktop motor in my AE86, and am trying to finish it up. I know it is an S13 Blacktop because it has ribs by the cam seals. It has an E5 ECU chipped my Yellowhat Sports Maintenance. The stock turbo outlet/O2 sensor housing came with a skinny (Titania type) sensor installed, but no wires in the sensor. I also have reason to believe that the turbo and/or o2 sensor housing may have been previously removed, even though this engine came straight from Japan.

The engine starts and runs without an o2 sensor installed, but I am trying to find the correct one for the best economy. I also have an AEM gauge-type UEGO installed. My question is this. I have searched and read many posts about this, and several state that the S13 Redtop and s13 blacktop use different o2 sensors. Some of these posts state that the S13Redtop uses the Titania sensor (skinny) and the s13 Blacktop uses the Zirconia sensor (fat). Since the 95 300zx Turbo sensor seems to be the Titania one, and the 87 300zx Turbo seems to be the Zirconia one, which should I use? Seems like I'd want to use the one that fits in my housing, but then again, what if someone's changed the housing? Seems like this would also be ECU-dependent, correct? If so, what to use with the E5 ECU?

Also, are ALL skinny sensors Titania (2%) and ALL fat sensors Zirconia (98%)? I would think so, but haven't been able to confirm this on my own. Any help appreciated.

[Darren]

The redtop (62) and blacktop (e5) ecus are virtually identical from everything i've read.... the only difference is that the blacktop ecu uses the fat o2 sensor, and the redtop uses the skinny.

You should be able to use the narrow band out from your AEM wideband in place of either though, especially if you have a programmable ecu

[will_drift_4_food]

That IS helpful, but I am still concerned that the two sensors are of different types and that the ECUs will read a different signal from each.

Why would my blacktop motor come with an o2 sensor and housing from a Redtop? Especially when I have a blacktop ECU? Maybe the previous Japanese owner/tuner just used an old Redtop housing as a replacement and ran the ECU in open loop the entire time? The turbo coolant lines had also been removed from the engine and the feed banjo tube welded shut, also the WG actuator had been shimmed with washers so I wouldn't doubt that other things were modded, lending credence to the fact that someone may have just bolted on a spare (S13 Redtop) housing. I've got a fat O2 sensor for an 87 300zx-T from Advance Auto that I want to install, but not if it is the wrong one.

The real question... Can anyone explain to me why my engine (which seems to start and run pretty well on an E5 ECU with no o2 sensor) came with a skinny sensor in its o2 housing, yet is seemingly supposed to use a FAT o2 sensor? If that sounds confusing, read it a couple of times. I had to.

Also, I think that my gauge only outputs a 0-5v (wideband) signal to the ECU, but if anyone knows how to change this, please let me know.

[Kingtal0n]

Your wideband should be able to configure a narrowband output, 0-1V. In fact you can program it to whatever Air/Fuel you want. In my car, I have it set to 15.2:1 air fuel (instead of 14.7) so that I cruise around with 15.2 and save some fuel.

You can use the fat O2 sensor in the redtop ECU- you just need to wire the signal wire correctly to the right input on the ECU. I have a #62 in my car and i used a generic 1-wire O2 sensor for over a year before switching to the Wideband simulated output.

and... some redtops came with those fins on the head... 91-92 model I believe.