02 Sensor Swap Information

Titania-type oxygen sensors are not compatible with zirconium type, and vise versa. Zirconium sensors relay a 0-1v signal and Titania sensors vary resistance to give the ECU its mixture feedback data. If you wanted to switch sensors to accommodate a 86-89T ECU, the wiring in the engine wiring harness would need to be changed, as well as the oxygen sensor bung (Titania are 17MM and Zirconium are 22MM). I grabbed this from jason's site!

Jersey88z wrote: I didn't think the o2 fitting/bung was the same thread where it screws into the o2 elbow. Sweet! Thanks.

UPDATE: the o2 fittings/bungs can be swapped from elbow to elbow for a T25 to T3 swap. :super
Another way woulda been getting an elbow from an 86-87 turbo which had T3s and Titania sensors. Also, Titania varies resistance 0-5v in most cases, not sure if the Z31s runs up to 5v or not.

On another note, I wired my 84T (running 86NA ECU /w Titania o2) like people claimed (grounding the yellow wire), Nistune reports back 0v at all times from the o2. So whoever came to the conclusion this way works, idk how much of that I believe.

Roach wrote: sooo. my 87 88 or 89 n/a ecu will work with my 88 turbo engine? with or without nistune just for it to start and tune?

bemis wrote: This Sticky was designed to address the issue of 02 sensor swapping, between Titania and Zirconia, due to engine harness or ECCS changes.

Using the information here, one should be able to easily swap 02 sensors if they have basic reading and wiring skills.

Here's the difference between the two sensors:





Here's how the two different 02 sensor styles are wired up according to the Factory Service Manual:



Here's a list of what kind of 02 sensor came with the Z31's from the factory:

1984-1985; 1987-1989 NA: Zirconia
1986 NA & Turbo: Titania
1987-1989 Turbo: Titania

The ECCS is designed to only use one type of 02 sensor, either Titania or Zirconia. No exceptions.

bemis wrote:

1984-1985; 1987-1989 NA: Zirconia
1986 NA & Turbo: Titania
1987-1989 Turbo: Titania

csgt428 wrote: I replaced my dead 88zx T25 with an 84 T3 turbo. When the oxygen sensor from my 88 didn't fit I cut the wires and used the 84 oxy sens with the 88 harness plug. They were both 3-wire with red white and black wires so I just used wire connectors and shrink wrap. The car seems to run fine, no issues even though the T3 oxy sens (I just discovered) is supposedly incompatible.....Am I running in "limp mode" or what? Will it hurt my ecu? It sounds like I could just swap out the bungs in the down pipes (assuming it will come out) but I'm not having any pre-ignition pinging or runability problems going on even though I'm using my 88 ecu. Everybody was saying I'd have problems but I'm not. (YET) Any ideas? I don't want to kill my ecu or damage the engine. If it is running a little richer due to the incorrect oxy sens mabey that's a good thing?

csgt428 wrote: Wow, that was fast. Thanx for the info. So, do you mean I can buy a new oxy sens for an 86-7 T3 turbo that will fit in my 84 T3 downpipe and plug into my 88 harness without changing the bungs out?