4 wire O2 sensor

[BlueBaron]

Can someone direct me to a site/picture or tell me how to make a 4 wire O2 sensor work on my car? (Unless '88 used them anyway)

I have an '88 harness and computer (from a SL) that plugs into an '87 bulkhead connector. I also have a TD model of the Dawes Device that I need to wire in as well.

________________________
*THE* Ean Orsel
http://www.thebluebaron.net
'87 LeBaron custom coupe

[als]

well the 2 white wires are power and ones ground the other is signal wire thats the one your a/f meter goes to. als when out and looked this is off of the 0/2 black sig. grey ground the to white wires are power/ALS

[contraption22]

Quote:

Originally Posted by als well the 2 white wires are power and ones ground the other is signal wire thats the one your a/f meter goes to. als when out and looked this is off of the 0/2 black sig. grey ground the to white wires are power/ALS

Actually no. There are two grounds, one power, and one signal.

[jdawg]

www.thedodgegarage.com says what color wires are what

[BlueBaron]

Ok, is this correct?

Wiring on the sensor itself (bought as '99 Intrepid unit)

White wire = heater
White wire = heater (one to 12v and one to ground obviously)
Grey wire = signal
Black wire = ground

There was resistance to the grey wire, meaning it's a signal lead.
That leaves the black one for ground to the sensor, but I didn't get a reading that it is connected to the threads on the sensor itself.

________________________
*THE* Ean Orsel
http://www.thebluebaron.net
'87 LeBaron custom coupe

[contraption22]

Ean, when i get home, i will check out mine and see what i did.

[Una]

Quote:

Originally Posted by BlueBaron Ok, is this correct? Wiring on the sensor itself (bought as '99 Intrepid unit) White wire = heater White wire = heater (one to 12v and one to ground obviously) Grey wire = signal Black wire = ground There was resistance to the grey wire, meaning it's a signal lead. That leaves the black one for ground to the sensor, but I didn't get a reading that it is connected to the threads on the sensor itself.

Yes, that's correct.
BTW, Love your barron.

[als]

hey in my FSM for 88 3 wire 0/2 said black is sig. wire / 91 powertrain 2.5l turbo 1 EFI{MPI** diagnostic proc. has the sig or output as BK/DG has BL/LB as sensor ground return, BL/TN asreference ground and last DG/BK as ASD voltage input i don,t have a 89 FSM so i still think my a/f meters run to the black one ALS ps the 91 FSM book is a lot more detailed than the 88 . it,s a must have if you got more than one car./van

[BlueBaron]

Thanks for the help guys. Here is the result:



The factory style plug plus a single connector to lead back to the battery ground.

________________________
*THE* Ean Orsel
http://www.thebluebaron.net
'87 LeBaron custom coupe

[minimopar]

Black should be signal and grey should be ground, but there is no hard-core standard here. It depends a bit on the brand. I always plug it into a cut-off 4-wire pigtail and check the colors there. Black with a light blue stripe is always signal ground for us.

[DakotaKid]

Thanks Russ.
I did as you said and now all is working good.

[The S is Silent]

Alright...here's another question about this: I have an 89 turbo mini and I'm installing a 2.2 TII motor while my 2.5 gets worked on. Can I use the stock 4 wire O2 sensor with the 88 TII SMEC with no problems?

What is the difference between the 3 and 4 wire O2 sensors if both are heated?

[87DANCEonYOU]

I always thought the wire should never be cut before the connector...but maybe it doenst make a difference.??

[Una]

Quote:

Originally Posted by The S is Silent Alright...here's another question about this: I have an 89 turbo mini and I'm installing a 2.2 TII motor while my 2.5 gets worked on. Can I use the stock 4 wire O2 sensor with the 88 TII SMEC with no problems? What is the difference between the 3 and 4 wire O2 sensors if both are heated?

Yes, the 4 wire works fine with the '88 electronics. Many people swap them in to even older cars, like '85 SC's and such which were only 1 wire.
The extra wire that a 4 wire has and a 3 wire doesn't is a signal ground. I've read that the new ground wire is to prevent a rusty exhaust manifold from messing with the signal. With such a low voltage signal that often gets read down to hundredths of a volt, the dedicated ground on the sensor makes for a very clean signal. On my megasquirted setup, I ran the signal and signal ground together back to the ECM as a twisted pair to prevent picking up any noise on the way back.

[minimopar]

Yep, the O2 sensor element itself did not change in many years. You can put an 4-wire sensor on a 1-wire car if you add the appropriate circuits. Depending on the year, the electronics will likely not go into closed loop mode any earlier with a heater sensor because they use a hard coded timer. Later years actually check the O2 voltage and decide based on that. The net result is that the A/F guage will show full rich for quite a while after cold startup instead of slowly coming up to full rich over a minute or so.