Ouch! Joey has a write up somewhere here on the repurposing! Good luck.
ARCHIVE Repurposing 95-97 Oxygen Sensors for 93-94 1FZs
- Thread starter NLXTACY
- Start date
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Rock Auto has the NTK sensors, about $250 for 2!
So I found myself in need of this info. A question on the diagram. In the final repinning, should the order be first row black-black, second row white-blue? The swap arrow leads to some confusion.
For anyone else doing this, some tips. The white tab in the center of the connecter can easily be removed completely from the connector by simply pulling it out. This makes it much easier to see what you are trying to do. Second, the pin locks need to be disengaged much further than one would initially think. They need to be pried up roughly 1/8". I used an exacto blade ground down to a long thin web, which worked well.
For anyone else doing this, some tips. The white tab in the center of the connecter can easily be removed completely from the connector by simply pulling it out. This makes it much easier to see what you are trying to do. Second, the pin locks need to be disengaged much further than one would initially think. They need to be pried up roughly 1/8". I used an exacto blade ground down to a long thin web, which worked well.
@NLXTACY Is there any advantage to using the 95-97 Denso Oxygen Sensors for 93-94? I see Wits' End now carries NTK: 80 Series NTK Oxygen Sensor- OBD1 Rear, Long Pigtail (93-94).
93yotasr5
Come and take it
So are the 95-97 sensors the same as the 93/94 but with different plugs and the wires are swapped for up/down stream?
95-97 OEM is Denso, 93-94 is NTK.
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94. So to summarize the re-purposing instructions I'm removing the old sensors from vehicle, removing those connector PINS, tossing the sensor and wires and saving only the connector housing(s).
Then with the new Denso sensor(s) I'm removing the connector pins, discarding the new Denso connector housing, and inserting those new Denso pins/wire/sensor back into the old connector housing according to the above pinout instructions. Plug back in, install, and away I merrily go.
Validation appreciated.
I will post back whether this works as a long term solution as opinions seem to vary wildly.
Then with the new Denso sensor(s) I'm removing the connector pins, discarding the new Denso connector housing, and inserting those new Denso pins/wire/sensor back into the old connector housing according to the above pinout instructions. Plug back in, install, and away I merrily go.
Validation appreciated.
I will post back whether this works as a long term solution as opinions seem to vary wildly.
Another alternative would be Denso 234-4520, which should fit without modification, see Denso 1994 Land Cruiser oxygen sensor question? Upstream/downstream - https://forum.ih8mud.com/threads/denso-1994-land-cruiser-oxygen-sensor-question-upstream-downstream.1157408/.
NTK part# 24044 (long lead) is now discontinued. NTK #24080 is (short lead for bank 2) is still available.
NTK part# 24044 (long lead) is now discontinued. NTK #24080 is (short lead for bank 2) is still available.
That is correct.
Thank you all and Scott for the validation. The NGK/NTK website now lists the 24044 as being "discontinued" which is why I'm going Denso.
A few notes from my 94 O2 sensor NTK to Denso transsensor surgery.
The OEM vehicle side of the housing is a single latch and opposite side has mount to connect to chassis. Both mine came apart with the help of a pick but not bad.
The OEM vehicle side of the housing is a single latch and opposite side has mount to connect to chassis. Both mine came apart with the help of a pick but not bad.
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To replace sensor side of the connector, first pull out the white piece then the pins with wires come out by bending the plastic tab forward on the housing and after disengaged sliding them out. Pretty simple.
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Slide the new Denso pins into the old OEM housing, pop the tabs back into place, and put the white piece back into connector. NOTE - the Denso sensors come BLACK BLACK top then WHITE BLUE bottom so I assumed the SWAP inferred that BLUE WHITE should be bottom row order. I hope inferred correctly.
About two weeks in with re-purposed Denso 4153s in both sides of my 94. I know my old sensors were toast and a very noticeable non-placebo difference in how the truck runs. Much crisper acceleration, no CEL, and we'll see about CO emissions in a few months. But so far all good.
My outer oxygen sensor popped out during a camping trip and I also went with the Denso 234-4153 to replace it.
I dremeled/sanded/filed down the keying on the new connector just plugged it in directly without swapping the blue/white leads. (Don't file down the notch that clips in to the snap fitting on the harness side)
Apparently the blue wire on Denso O2 sensors carries the signal and white is ground. The pair of black leads powers the heater/resistor, which isn't polarity dependent.
The EWD shows the colors of the wiring on the harness side.
Before tracing this out, I followed effjay80's tutorial and swapped the blue/white leads on the new o2 sensor. I kept getting a code 25 and 26 within a minute or two of starting the engine. The CEL would intermittently go out but consistently come back. Maybe the PO repinned my harness? I traced these wires in the EWD and ended up returning the blue/white leads to the original position, which quickly made the CEL go away and it hasn't come back for the past 50 miles. If in doubt just look at the harness side and match the colors according to the EWD.
I dremeled/sanded/filed down the keying on the new connector just plugged it in directly without swapping the blue/white leads. (Don't file down the notch that clips in to the snap fitting on the harness side)
Apparently the blue wire on Denso O2 sensors carries the signal and white is ground. The pair of black leads powers the heater/resistor, which isn't polarity dependent.
| Pin#, harness side | Signal name | Denso wire color (sensor side) |
| 1 | HT1/HT2 | Black |
| 2 | +B | Black |
| 3 | OX1/OX2 (signal) | Blue |
| 4 | OX1+/OX2+ (ground, tied together in EWD) | White |
The EWD shows the colors of the wiring on the harness side.
Before tracing this out, I followed effjay80's tutorial and swapped the blue/white leads on the new o2 sensor. I kept getting a code 25 and 26 within a minute or two of starting the engine. The CEL would intermittently go out but consistently come back. Maybe the PO repinned my harness? I traced these wires in the EWD and ended up returning the blue/white leads to the original position, which quickly made the CEL go away and it hasn't come back for the past 50 miles. If in doubt just look at the harness side and match the colors according to the EWD.
Yes I also noticed post-hoc that the only difference between the housing on the Denso sensors vs. NGK are the alignment tabs which can be filed/sanded/dremeled off as needed to fit. So really no need to swap the connectors so long as your signals are in right spot.
So after I thought I had correctly I was experiencing a rough idle and check engine light (26, rich condition). Just a few minutes ago I climbed under the LC and verified that I did the short pigtail wrong, so I pulled it and re-did it and I now have a smoother idle and no check engine light. Time to get this bastard emission tested and registered.
