20v O2 sensor type

[AdrianS]

I'm having a downpipe made for my blacktop mr2 swap, and would like to go universal O2 sensor, if I can find a suitable sensor. I hope to find a cheaper sensor than Toyota's ridiculous price.
As I'm getting the pipe made up, I can go with any flange / mount I like for the sensor.

From this thread http://www.toymods.org.au/forums/showthread.php?t=38499, the toyota part # is :

89465-19685

But what are the sensor specs ?

From http://www.toymods.org.au/forums/showthread.php?t=52141

heater resistance - ~6 ohms (blacktop AE111 is ~12 Ohms).

and http://www.toymods.org.au/forums/showthread.php?t=2019

Only difference i know of is heater resistance; gze/silvertop is ~7 ohms, blacktop is ~14.

So -
heater resistance ~12 Ohm, and we know it's 4 wire.

From the web, a list of sensor types :

Zirconia 'thimble' type
Element type - zirconium dioxide, thimble
Types available - one, two, three and four wire, 18mm thread
Heater resistance - (3 and 4 wire sensors only) 2 to 6.5 ohms
Output signal - oscillating 0.1 and 0.9 volts

Zirconia thick film type
Element type - zirconium dioxide, planar
Types available four wire, 18mm thread
Heater resistance - 12 to 15 ohms
Output signal - oscillating between 0.1 and 0.9 volts

Titania
Element type - titanium dioxide, planar
Types available - three and four wire 12mm and 18mm thread
Heater resistance - 4 to 7 ohms.
Output signal - oscillating between 0 and 1 volt or between 0 and 5 volts
(depending on make and number of wires)

Lean Burn
Element type - zirconium dioxide, thimble or planar
Types available - four wire, 18mm thread
Heater resistance - 1.8 to 2.2 ohms
Output signal - discrete voltage levels between 0 and 5 volts


Thus Silvertop = Zirconia thimble, Blacktop = Zirconia planar.
Makes sense - planar is newer tech, titania came after the 20v.

Remaining question- is the toyota sensor grounded or isolated case ?


Possible "generic" sensors :


Twos R Us sells Denso #234-9011 as a blacktop sensor, which is also used by the subaru 2002-5 WRX (USDM), so that looks like a good, readily available sensor, but I can't find any specifications data on it. They also want $US 150-, so I'm checking alternatives.

From the bosch sensor catalog, their 12 watt universal sensors are :

• [i]258 005 728 – Four wire sensor with 12 watt heater, grounded case, “flange” type mounting. And special protection tube.
  - I don't want flange type
• 258 005 729 – Four wire sensor with 12 watt heater, isolated ground, 3 slot protection tube
• 258 005 732 – Four wire sensor with 12 watt heater, grounded case and special protection tube
• 258 986 506 – Four wire sensor with 12 watt heater and grounded case.
• 258 986 507 – Four wire sensor with 12 watt heater and ground isolated case.

So - what the f** is the "special protection tube" ?

I would assume the best Bosch match would be :
258 986 506 – Four wire sensor with 12 watt heater and grounded case.
or
258 986 507 – Four wire sensor with 12 watt heater and ground isolated case.

depending on ground requirements. And the "special protection tube", which I will ignore for now.

Sorry for the length.

[AdrianS]

Done some more cross-referencing against the Denso part from TwosRus (234-9011)

It matches :
ACDelco 213-2843
NTK 24659
Subaru 22641AA042
Bosch 15537 - which I can't find in my Bosch catalog !

Bosch listings for the Subaru family tend to be 258 005 732, which is grounded case ?

edit : the bosch 15537 seems to be a wideband - that can't be right ? Is the denso sold by TwosRUs a wideband ? I'm confused now !

[Z2TT]

Special protection tube I think is the heat resistant boot that covers the wiring.

So long as you get a sensor with the same resistance for the heater circuit you should be fine

Contact these guys - http://www.hiflo.com.au/

See if they have an oxygen sensor with the resistance for the heater you need, they have previously tested their sensors when I asked them to before selling to me. But I take it that a 12 watt heater element will have around 12 ohm resistance which is what you need? so one of the bosch universal sensors is what you want

3 wire sensors will work just will be grounded via case rather than a dedicated wire.