4 wire Oxygen sensor installed
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4 wire Oxygen sensor installed
Here's reference post....for those that haven't read it.
http://bbs.legacycentral.org/viewtopic. ... ensors+com
I just installed this last night, and lemme say....wow.....I don't think my car has ever idled as good as it does now!! Idle is pretty much rock solid. There seems to be a little more power/smoothness in the mid-range rpms. Hopefully my mpg will increase as well. Just have to wait and find out.
Re the sensor itself, it's a good unit, the only thing that was crap was the generic directions. They are incorrect in terms of what wire to hook up to what. So if anyone does this mod, don't use their directions. I'll have to double check, but I believe that the white wire on the OEM sensor is the actual sensor wire. The red & black are the power & ground wires.
For 50 bucks, this was a nice upgrade. I messed up during install and forgot to put the shrink wrap sleeves on one of the wires, so I had to cut it off, then redo it, but I had to add an extra piece of wire in there because it was too short......it was a mess.....anyway....make sure you have the shrink wrap on the wire before you do your final crimp.....or you'll be SOL.
http://bbs.legacycentral.org/viewtopic. ... ensors+com
I just installed this last night, and lemme say....wow.....I don't think my car has ever idled as good as it does now!! Idle is pretty much rock solid. There seems to be a little more power/smoothness in the mid-range rpms. Hopefully my mpg will increase as well. Just have to wait and find out.
Re the sensor itself, it's a good unit, the only thing that was crap was the generic directions. They are incorrect in terms of what wire to hook up to what. So if anyone does this mod, don't use their directions. I'll have to double check, but I believe that the white wire on the OEM sensor is the actual sensor wire. The red & black are the power & ground wires.
For 50 bucks, this was a nice upgrade. I messed up during install and forgot to put the shrink wrap sleeves on one of the wires, so I had to cut it off, then redo it, but I had to add an extra piece of wire in there because it was too short......it was a mess.....anyway....make sure you have the shrink wrap on the wire before you do your final crimp.....or you'll be SOL.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
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- Vikash
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That's great that you saw such an improvement. How old was the 3-wire sensor you took out? I'm wondering if we should attribute all the improvement to just the separate ground.
Where did you connect the sensor ground wire? Did you use -K-'s idea and just use the heater ground?
Just to note, the wire colors are different on the harness side and the sensor side of the connector.
You're right -- on the sensor side, white is signal, black is heater ground, and red is heater +12v. Technically the heater isn't polarity-sensitive, I think, but that's how it's wired. On the harness side, white is signal again, black-with-white-stripe is heater ground, and yellow-with-red-stripe is heater +12v.
Where did you connect the sensor ground wire? Did you use -K-'s idea and just use the heater ground?
Just to note, the wire colors are different on the harness side and the sensor side of the connector.
You're right -- on the sensor side, white is signal, black is heater ground, and red is heater +12v. Technically the heater isn't polarity-sensitive, I think, but that's how it's wired. On the harness side, white is signal again, black-with-white-stripe is heater ground, and yellow-with-red-stripe is heater +12v.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
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- quasi-mod-o
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Okay. This sounds like something I want to take a swing at. However, let me see if I gathered this correctly from the other thread, we all know I'm not the electric whiz around here
I will remove my old sensor, steal the connector off of it, and splice the connector onto the corresponding 3 wires on the new O2 sensor. Therefore it will plug right into the wiring harness. Then I will find a way to attach the 4th wire (the ground wire) to the body somewhere nearby, effectively giving a better ground, and hopefully a more accurate sensor.
Is that the way of it?
I will remove my old sensor, steal the connector off of it, and splice the connector onto the corresponding 3 wires on the new O2 sensor. Therefore it will plug right into the wiring harness. Then I will find a way to attach the 4th wire (the ground wire) to the body somewhere nearby, effectively giving a better ground, and hopefully a more accurate sensor.
Is that the way of it?
2000 Subaru Legacy B4 RSK
"Der Wahnsinn ist nur eine schmale Brücke/die Ufer sind Vernunft und Trieb"
*Formerly DerFahrer*
@entirelyturbo on social media, including Facebook, Instagram, Twitter, and TikTok
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- Vikash
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I would recommend splicing the 4th wire (sensor ground) together with the heater ground wire that's already on the harness. The heater ground does go to the ECU. But, yes, what you wrote seems correct; Josh can clarify.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
The sensor I pulled out I put in around 121k miles, sept-oct 98. I currently have 174k miles.
It's possible the sensor was getting lazy......but after seeing how rusted the head bolts were and everything.....I'm sure it wasn't getting the best ground.
I connected the sensor ground to the heater ground. It goes to the ECU, as good as place as any for it to go.
Yes wire colors are different on engine side........the heater is not polarity sensitive.....instructions even say so.
subyluvr, if you do this, make sure you leave yourself some extra wire length in the event you do a boo boo like I did, and make sure you have the shrink wrap on.....and splice the sensor ground with the heater ground.
It's possible the sensor was getting lazy......but after seeing how rusted the head bolts were and everything.....I'm sure it wasn't getting the best ground.
I connected the sensor ground to the heater ground. It goes to the ECU, as good as place as any for it to go.
Yes wire colors are different on engine side........the heater is not polarity sensitive.....instructions even say so.
subyluvr, if you do this, make sure you leave yourself some extra wire length in the event you do a boo boo like I did, and make sure you have the shrink wrap on.....and splice the sensor ground with the heater ground.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
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- quasi-mod-o
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Okay so the wire colors on my old sensor and the one I'm going to buy are the same? Meaning splicing them together will be easy as far as identification goes?
Except for the heater ground, which (on the wiring harness) is a different color wire than the sensor? I am bypassing the plug when I wire in the heater ground sensor to the wiring harness, right? What colors am I looking for here? Josh, I'll buy the same sensor that you bought for simplicity...
Also, Josh, after a tank or two of gas, can you report back and tell us how your mileage has changed?
Except for the heater ground, which (on the wiring harness) is a different color wire than the sensor? I am bypassing the plug when I wire in the heater ground sensor to the wiring harness, right? What colors am I looking for here? Josh, I'll buy the same sensor that you bought for simplicity...
Also, Josh, after a tank or two of gas, can you report back and tell us how your mileage has changed?
2000 Subaru Legacy B4 RSK
"Der Wahnsinn ist nur eine schmale Brücke/die Ufer sind Vernunft und Trieb"
*Formerly DerFahrer*
@entirelyturbo on social media, including Facebook, Instagram, Twitter, and TikTok
"Der Wahnsinn ist nur eine schmale Brücke/die Ufer sind Vernunft und Trieb"
*Formerly DerFahrer*
@entirelyturbo on social media, including Facebook, Instagram, Twitter, and TikTok
The colors on the 4-wire sensor are not the same, however they are labeled on the instructions. The colors are like blue, white, & black....or something of that nature.
I wrote down the color coding on the directions.....I'll post them when I get home tonight.
You are not bypassing anything. You're hooking both ground wires together. I'll post the little color coding thing....that might help......if not...email or IM me.....and I'll try to explain it.
I'll keep ya posted on the mpg too.
I wrote down the color coding on the directions.....I'll post them when I get home tonight.
You are not bypassing anything. You're hooking both ground wires together. I'll post the little color coding thing....that might help......if not...email or IM me.....and I'll try to explain it.
I'll keep ya posted on the mpg too.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
Ok, here's what the wires are & what you connect what to what.
OEM O2 sensor wires
Black = Heater Ground
Red = Heater 12v+
White = O2 Sensor
Walker Generic 4-wire O2 sensor wires
Blue = O2 Sensor
White = Sensor Ground
Black = Heater Ground
Black = Heater 12v+
Since the heater is not polarity dependent, it doesn't matter which black wire you use at ground and 12v+.
When you hook things up
Hook OEM white wire to Walker blue wire
Hook OEM red wire to one of the Walker black wires
Hook OEM black wire to Walker's white & other black wire.
questions?
OEM O2 sensor wires
Black = Heater Ground
Red = Heater 12v+
White = O2 Sensor
Walker Generic 4-wire O2 sensor wires
Blue = O2 Sensor
White = Sensor Ground
Black = Heater Ground
Black = Heater 12v+
Since the heater is not polarity dependent, it doesn't matter which black wire you use at ground and 12v+.
When you hook things up
Hook OEM white wire to Walker blue wire
Hook OEM red wire to one of the Walker black wires
Hook OEM black wire to Walker's white & other black wire.
questions?
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
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- Vikash
- Posts: 12517
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Nice concise color-coded instructions. :) For clarity's sake -- you cut the connector off of the stock sensor and spliced it in with the Walker sensor, discarding the stock sensor itself, correct?
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
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- quasi-mod-o
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- Joined: Thu Dec 05, 2002 7:06 pm
- Location: Tampa, FL
Sweet!
Awesome instructions, Josh. Makes perfect sense.... I'll get a sensor soon, and VERY soon since I just measured my mileage for a 250-mile trip, nothing but highway... 24 mpg... terrible...
Awesome instructions, Josh. Makes perfect sense.... I'll get a sensor soon, and VERY soon since I just measured my mileage for a 250-mile trip, nothing but highway... 24 mpg... terrible...
2000 Subaru Legacy B4 RSK
"Der Wahnsinn ist nur eine schmale Brücke/die Ufer sind Vernunft und Trieb"
*Formerly DerFahrer*
@entirelyturbo on social media, including Facebook, Instagram, Twitter, and TikTok
"Der Wahnsinn ist nur eine schmale Brücke/die Ufer sind Vernunft und Trieb"
*Formerly DerFahrer*
@entirelyturbo on social media, including Facebook, Instagram, Twitter, and TikTok
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- Knowledgeable
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The extra wire is for grounding since a 3 wire sensor grounds through the body of the sensor itself which would be the exhaust manifold most of which are rusty. Correct me if I'm wrong.
Rio Red 90 Legacy LS AWD 174k
Liquid Silver 92 SVX LS-L 88k
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Liquid Silver 92 SVX LS-L 88k
[url=http://folding.amdmbpond.com/FoldingForOurFuture.html]Do you fold?[/url]
I'm on First and First. How can the same street intersect with itself? I must be at the nexus of the universe.
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- quasi-mod-o
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- Location: Tampa, FL
Right. My exhaust isn't all that terribly bad, kinda yucky-looking but not like it came from the bottom of the ocean However, grounding through the ECU will still probably provide a more accurate reading than through the exhaust...
2000 Subaru Legacy B4 RSK
"Der Wahnsinn ist nur eine schmale Brücke/die Ufer sind Vernunft und Trieb"
*Formerly DerFahrer*
@entirelyturbo on social media, including Facebook, Instagram, Twitter, and TikTok
"Der Wahnsinn ist nur eine schmale Brücke/die Ufer sind Vernunft und Trieb"
*Formerly DerFahrer*
@entirelyturbo on social media, including Facebook, Instagram, Twitter, and TikTok
correct.....I still kept the stock sensor, but it's not worth anything.vrg3 wrote:Nice concise color-coded instructions. For clarity's sake -- you cut the connector off of the stock sensor and spliced it in with the Walker sensor, discarding the stock sensor itself, correct?
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
If things work out with the 4 wire O2 Sensor, then I might consider doing it sometime. Right now my car is getting around 16mpg in the City, and about 23 on the highway, and I want to increase both of these numbers.
[color=red][b]1993 Subaru BC Turbo Legacy (193k miles)
1971 VW Super Beetle
1989 Honda Elite 50
[/color][/b]
1971 VW Super Beetle
1989 Honda Elite 50
[/color][/b]
So better late than never, during my vacation from the board I did the exact same thing. I too decided to run the ground for the sensor and heater back to the ecu together.
For the most part I agree with everything said so far, except the performance gains which I cant verify since other changes had been made to the car at the same time. I do know the car is better than before though and my old sensor was only 35k miles old!
For my turbo project I also plan to use a 4 wire sensor, except relocate farther down the DP that what is stock.
For the most part I agree with everything said so far, except the performance gains which I cant verify since other changes had been made to the car at the same time. I do know the car is better than before though and my old sensor was only 35k miles old!
For my turbo project I also plan to use a 4 wire sensor, except relocate farther down the DP that what is stock.
Everything seems to be working very well. I don't really have many miles on the car, just because I live so close to work, and my mileage is also going to suck because of it too.......if I ever get a good highway mileage trip, I'll try and see how the mileage goes.
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
tight....but not too tight
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
I just used my crescent wrench, so yeah a box end wrench should work fine
Josh
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
surrealmirage.com/subaru
1990 Legacy (AWD, 6MT, & EJ22T Swap)
2020 Outback Limted XT
If you need to get a hold of me please email me rather then pm
I got my Sensor in today, and I ended up using an O2 sensor wrench, since I couldn't get the Box end in there. I also found the tourque spec is 35 ft/lbs. I however didn't use my tourque wrench because I couldn't get it to fit. Should I worry about over-tightening it, since I got it in there very snug???
[color=red][b]1993 Subaru BC Turbo Legacy (193k miles)
1971 VW Super Beetle
1989 Honda Elite 50
[/color][/b]
1971 VW Super Beetle
1989 Honda Elite 50
[/color][/b]