I ordered a new O2 sensor for my 96 Dakota V6. The sensor that came (mail order) has a different plug, but same color wires (2 whites, 1 black, 1 grey) they are in different order on both plugs. Sensor is the same size and thread and I had it fit nicely before I noticed the plugs.
So what does the GRM braintrust say? Is it ok to splice the wires into the original sensor, or should I send it back for a new one?
Many O2 sensors are universal and meant to be spliced.
Cut and paste. No worries. As long as you have a good connection it will be fine. Resistance is the enemy since it will throw off the numbers.
Having said that... did you order direct replacements? If so, they sent you the wrong thing. If you ordered multi-fit or universal sensors, then its up to you to splice.
I just took a second look at what I ordered. The part was xxxx and there is a xxxxt right next to it in the list. The one I ordered was for a 89-93 and the xxxxt is for a 93-98. They are both listed for a 96, you have to click an additional cross reference list to see the difference.
Cut and splice as close to the plug as possible (sensor breathes through the wiring so you want the longest uninterrupted length of wire possible before the plug). Crimp, never solder. Make sure to heat shrink your connections well and you'll have nary a problem.
I do this all the time, since the Ford 5.0 four-wire sensor is cheaper than the universal and is exactly the same except for the plug.
SlickDizzy wrote: Crimp, never solder. Make sure to heat shrink your connections well and you'll have nary a problem.
Yep This^^^
Why do you never solder? I din't technically solder my connection, but I soldered a new lead down to the connection.
In reply to spitfirebill:
I have trouble with that one also. Every crimped connection I've ever seen has been weak and prone to failure. Every soldered connection I've ever seen has been secure and unbreakable. And still they say that in an automotive environment the crimp is superior. I've heard it a thousand times, yet deep down, I don't believe it. Not for a second.
The reason O2 sensors are crimped and NEVER soldered is because the solder point adds resistance to the wire and will throw off your sensor readings since it "breathes" through the wire. Soldering voids the warranty for many brands for this very reason.
This is not a statement about all automotive wire connections, this is a statement about O2 sensors specifically.
Please elaborate on "breathing" through the wire.
Are the pins inside the connector shaped the same? It may be as easy as sliding the pins out of the new connector and into the old one.
motomoron wrote: Please elaborate on "breathing" through the wire.
Okay.
http://www.autotap.com/techlibrary/understanding_oxygen_sensors.asp
Older style oxygen sensors actually have a small hole in the body shell so air can enter the sensor, but newer style O2 sensors "breathe" through their wire connectors and have no vent hole. It's hard to believe, but the tiny amount of space between the insulation and wire provides enough room for air to seep into the sensor (for this reason, grease should never be used on O2 sensor connectors because it can block the flow of air). Venting the sensor through the wires rather than with a hole in the body reduces the risk of dirt or water contamination that could foul the sensor from the inside and cause it to fail. The difference in oxygen levels between the exhaust and outside air within the sensor causes voltage to flow through the ceramic bulb. The greater the difference, the higher the voltage reading.
Just remember the "vent wire" thing, where the sensor uses the wire insulation as a ventilation tube. Make sure you don't seal it up too well, maybe strip the insulation far back, solder & shrink wrap.
Edit: Whoops, turns out I'm an idiot, don't solder.
No soldered connections on aircraft as well. Vibes cause failures.
Well I have one of the older style sensors, so I hope I'm OK. Plus the soldered connection is 2 feet upstream from the connection. I replaced the lead to the connector because it had gotten brittle and cracked. But, I learned something tonight.
1988RedT2 wrote: In reply to spitfirebill: I have trouble with that one also. Every crimped connection I've ever seen has been weak and prone to failure. Every soldered connection I've ever seen has been secure and unbreakable. And still they say that in an automotive environment the crimp is superior. I've heard it a thousand times, yet deep down, I don't believe it. Not for a second.
Outside of the computers, find one solder joint in a car.
Also, when counting on a more reliable connection, instead of solder, it was better to have gold plating. Think about that- it's easy to solder for production, since fuel rails are done that way. Cheap, fast, economical- yet not used.
Good crimps >> solder.
And I do mean good crimps. Not the crappy ones that are thin metal with plastic covering them. Good ones. And good crimping tools.
SlickDizzy wrote: The reason O2 sensors are crimped and NEVER soldered is because the solder point adds resistance to the wire and will throw off your sensor readings since it "breathes" through the wire. Soldering voids the warranty for many brands for this very reason. This is not a statement about all automotive wire connections, this is a statement about O2 sensors specifically.
In a word, NO! ("breathes" through the wire? Really?)
The resistance of either type joint is in the range of a few milli-ohms, low enough that it takes specialized equipment to even measure it.
Meanwhile, O2 sensors are VOLTAGE devices, the amount of current that flows is on the order of milliamps, joint resistance is irrelavant.
Crimps are used by OEM because they yield a reliable electrical and mechanical joint, quicker and easier with automated equipment (ie cheaper).
erohslc wrote:SlickDizzy wrote: The reason O2 sensors are crimped and NEVER soldered is because the solder point adds resistance to the wire and will throw off your sensor readings since it "breathes" through the wire. Soldering voids the warranty for many brands for this very reason. This is not a statement about all automotive wire connections, this is a statement about O2 sensors specifically.In a word, NO! ("breathes" through the wire? Really?)
SlickDizzy wrote:motomoron wrote: Please elaborate on "breathing" through the wire.Okay. http://www.autotap.com/techlibrary/understanding_oxygen_sensors.aspOlder style oxygen sensors actually have a small hole in the body shell so air can enter the sensor, but newer style O2 sensors "breathe" through their wire connectors and have no vent hole. It's hard to believe, but the tiny amount of space between the insulation and wire provides enough room for air to seep into the sensor (for this reason, grease should never be used on O2 sensor connectors because it can block the flow of air). Venting the sensor through the wires rather than with a hole in the body reduces the risk of dirt or water contamination that could foul the sensor from the inside and cause it to fail. The difference in oxygen levels between the exhaust and outside air within the sensor causes voltage to flow through the ceramic bulb. The greater the difference, the higher the voltage reading.
Derp.
Maybe another source will drive the point home.
http://www.linnbenton.edu/auto/scope/o2.htm
Older style oxygen sensors have a small hole in the body so air can enter the sensor, but newer style sensors breathe through their wire connectors and have no vent hole. Grease should never be applied to the wires where they enter the sensor, because it would prevent proper air circulation. So will dirt and other contaminates.
In reply to erohslc:
How about look at the question in a different manner? It's easy to ask WHY the sensor needs to breath in the first place. The answer to that is that the voltage that you correctly point out that is gotten is generated by the small catalyst generating that voltage based on the difference of partial pressure of O2 across it. High is a big difference, low is low difference, and the voltage quickly changes as the chemistry passes through stoichiometry.
As slick posted, old sensors had a hole near the sensor, but that turned out to be unreliable due to the location of where the sensor lives. So using the right wire, enough air is in the sensor to work well.
WB sensors are interesting in that they actively move the air into the thimble area, which makes it a lot more robust in terms of voltage to O2- hense it works more "smoothly" across a wide range of O2.
Glad I'm not crazy, I'm tired of people looking at me like I've just claimed the world is flat when I say they breathe through the wires...
I like to cut pieces of copper tubing (the small kind for oil pressure gauges) and use those with shrink wrap over top for splices. Much cheaper than the plastic coated stuff and you get a more solid crimp.
jere wrote: I like to cut pieces of copper tubing (the small kind for oil pressure gauges) and use those with shrink wrap over top for splices. Much cheaper than the plastic coated stuff and you get a more solid crimp.
That sounds like a good idea, I'll have to try that sometime!
hi im building a vw trike . im putting efi on that has 1 o2 sensor. can i spice in a second o2 sensor. i have dual exhaust so single o2 sensor will not read cylinders 1 and 2.
thank david
All I can say, I will never use universal O2 sensors again. Nor will I use generic brands. I put generic on my Rover and it hated them. Had to shell out the big bucks for the dealer supplied ones ON TOP of the money I spent for the "just as good" generics.
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