O2 sensor question
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O2 sensor question
Hello all, I have an 85 bronco with the AOD trans and fuel injected 302. I had my 14 year old son swap out the O2 sensor and he is not sure what wire it was connected to. I dont know because I was never down there. He found one that is black and runs down from the firewall. I was wondering if anyone out there had a picture of this so I could be sure I have right wire or not. Thanks in advance for any help.
Lead Driver
Joined: Sep 2002
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From: Gateway to the West
The O2 sensor has a three-wire connector with a GREY/YELLOW, GREEN/PURPLE, and a BLACK wire. The GREEN/PURPLE sends readings to the ECM. The GREY/YELLOW is the power in from the ignition to heat the sensor. The BLACK is the negative (ground) to complete the circuits.
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Junior User
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After consulting my haynes manual,the sensor is correctly called an HO2S or HGEO sensor. The only three wire sensor I found was green,orange,black, but I think that is my MAP sensor. My o2 sensor has one black wire. Im having the same problem as Cdy1 is having...engine running rich.
Lead Driver
Joined: Sep 2002
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From: Gateway to the West
Older O2 sensors that do NOT self-heat simply send the signal back to the ECM via a single wire. Since the voltage generated by an O2 sensor is dependent on the chemical reaction that occurs when the sensor reaches a certain temperature, early units don't actually start sending signal/information until the exhaust system has heated them.
I have no information for the 85 EFI models so I was referencing 86 model year which DOES utilize a HEGO sensor (self heating unit that requires the other two wires to heat the sensor so it begins sending information to the ECM almost immediately).
I have no information for the 85 EFI models so I was referencing 86 model year which DOES utilize a HEGO sensor (self heating unit that requires the other two wires to heat the sensor so it begins sending information to the ECM almost immediately).
Hotshot
Joined: Jul 2002
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From: Bend,OR
on my 94 the o2 sensor wire is loomed in with the starter cable. not sure if that will help you or not. the plug for the o2 is specific to only that part so i would assume if it fits then you have the correct wire.
Lead Driver
Joined: Sep 2002
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From: Gateway to the West
Yeah, Kem that's what I thought too but after what the guys said about it, the 85 EFI models (since they would be the first models with an O2 sensor... carb'd models didn't need one) could well use the old oxygen sensor that doesn't have the pre-heat circuit/element in it. If that is the case, the sensor could very well have only one wire running to it from the ECM.
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dancing4raiin
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
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Dec 1, 2012 09:38 AM
