4-wire O2

[gears351]

So I keep getting an O2 code rich fault on my 2.5 T2 SMEC in my Dakota - turns out I ran the 3 wire O2 from an 88 wire harness and it's likely getting interference on the signal.

Will any NB O2 work for this? I remember years ago putting a universal 4 wire bosch in my Durango and the instructions were specific about cutting the wires exactly the same length as the oem one.

I've got a few old 4 wires setting around and figured I'd cut and splice the connector into my 3 wire harness and run a separate connection for that SMEC sensor ground.

Will this work or am I creating more problems for myself?

Thanks

[HSKR]

I'd personally suggest finding the proper 4-wire engine harness connector and wiring it up to the factory harness with the 4-th wire ran to the SMEC and buy a plug and play NTK O2 sensors instead of cutting and splicing the wires on the O2 sensor itself. Will make for easier O2 sensor changes in the future. Basically, do it right the first time.

[gears351]

HSKR, I've got "Do it right or do it over" painted on our family's quote wall.... that being said, I happen to have a 4 wire lying around (from a jeep) and I don't have the proper 4wire plug for the wiring harness. This is a transplant into a truck with a hybrid wiring harness between an 89 Daytona and a 90 truck. It was my understanding that a 4 wire has + - for the heating element and + - for the SMEC signal. This is compared to the 3 wire Heat, Signal, and Ground harness.

[HSKR]

Yeah, there is a difference. I was suggesting hitting up a junkyard and cutting a 4-wire plug off the engine harness from pretty much any vehicle that has one. Just make sure you remember what vehicle you got it off of because you will need to buy O2 sensors that fit that plug.

[boboli]

HSKR, I've got "Do it right or do it over" painted on our family's quote wall.... that being said, I happen to have a 4 wire lying around (from a jeep) and I don't have the proper 4wire plug for the wiring harness. This is a transplant into a truck with a hybrid wiring harness between an 89 Daytona and a 90 truck. It was my understanding that a 4 wire has + - for the heating element and + - for the SMEC signal. This is compared to the 3 wire Heat, Signal, and Ground harness.

I'm pretty certain you are right about the wiring for a 4 wire O2 sensor. My omni originally had a 1 wire sensor. I bought a 4 wire sensor from a 90's voyager and added 3 wires. If I remember correctly, 2 are grounds ( 1 to battery, other to the sensor grounds, I.e common ground point for tps, iac, map, etc). The last is a switched 12v for O2 heater. This was added to quicken the accuracy of the O2 sensor. A factory plug helps with replacement issues, but any 4 wire plug can be made to work with your choice of sensor