o2 sensor question
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Elder User
Joined: Jun 2002
Posts: 812
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From: Woodbridge NJ
o2 sensor question
Has anyone spliced or extended their wiring harness on their oxygen sensor? I have long tube headers and the bung is on the exhaust pipe after the header collector....so I'm about 8" short.
Does anyone see any problems with me extending the 4 wire harness for the sensor. I will solder the connections and use larger gauge wire that the harness is made of.
Thanks for any responses.
Jerry D.
Does anyone see any problems with me extending the 4 wire harness for the sensor. I will solder the connections and use larger gauge wire that the harness is made of.
Thanks for any responses.
Jerry D.
New User
Joined: Nov 2005
Posts: 4
Likes: 0
Here is some useful information that I can pass on to you from my extensive electronics training. A four wire sensor requires that all the wires be of the same type and gauge. So, it should be all right to add and extension as long as this rule is followed.
A four-wire sensor configuration is used with an RTD type sensor. RTD's are made with a heat sensitive resistor. Hence, the resistance changes with heat. The two wires going to the sensor also have resistance and therefore add a certain amount of resistance to the sensing loop. A more accurate reading is obtained when the resistance of these wires are eliminated from the sensing loop. Without bogging you down with a ton of theory, the two extra wires are used by the interface circuit to calculate the wires resistance. This value is then subtracted from the actual sensed value.
So, just make sure that all the wires used on the extension are of the same type (ie., from the same spool of wire), same exact length, and that the wire gauge is the same as that of the sensor wiring.
I hope this helps out
joe
A four-wire sensor configuration is used with an RTD type sensor. RTD's are made with a heat sensitive resistor. Hence, the resistance changes with heat. The two wires going to the sensor also have resistance and therefore add a certain amount of resistance to the sensing loop. A more accurate reading is obtained when the resistance of these wires are eliminated from the sensing loop. Without bogging you down with a ton of theory, the two extra wires are used by the interface circuit to calculate the wires resistance. This value is then subtracted from the actual sensed value.
So, just make sure that all the wires used on the extension are of the same type (ie., from the same spool of wire), same exact length, and that the wire gauge is the same as that of the sensor wiring.
I hope this helps out
joe
Lead Driver
Joined: Nov 2002
Posts: 9,555
Likes: 40
From: Concord, NC
O2 sensors generate a voltage which is sent to the computer. The computer does not measure a resistance through the O2 sensor sensing element. I agree that when extending wiring that the same gauge wire should be used for the extensions, but the computer isn't precise enough to know a slight difference.
