Thread: Regrounding the O2 Sensor

Nope, completely different... They are not the same in multiple ways.. The voltage ranges are different, signal types are different, some thread pitches are different and the size can be different as some are longer than others. Ive already experienced the latter 2 items with aftermarket O2 replacements. But MOST important is the voltage range. Your ECU is expecting voltage reading across about a 1 volt range. I think ours is .1 to .9 but Im not sure. Will need to look it up.. But if your sensor is in another range, the ecu will either trigger a CEL or try to adjust for the out-of-range signals; both are not good..

I actually talked to a tech at Bocsh and they only manufactured ONE equvalent 4 wire O2 sensor. If its not that ONE, I wouldnt use it!

I really hope the eBay guy sent me the O2 sensor that I requested hehe, I guess I'll be checking for a Cell to make sure. Or if no or worse gas mileage happens.

DC Scotty,

Do you have any updates for us?

I will be filling up soon to see how the 4-wire sensor did.

Now during the time my front Heater fuse was shot and I wasn't nice on the car

Nope, no updates yet. This is a small shop and slow getting parts. The O2 sensor will be in tomorrow afternoon. I will pickup on my way home. I will install it over the weekend.

Well I'm almost done making the resistor mod for the Rear O2 sensor. As soon it is finished and it assures the CEL not to come back on I'll be doing the Gas mileage test to see how well it works

Great news! Let us know what you find..
Im thinking your gas mileage will get better automatically due to the rear O2 sensor.

Well see, this car has been under 20mpg (city only), since I installed the header.

This thread has made me realize something that could have been a cause for my wideband 02 sensor controller failure, but I'm not sure about it. It just died randomly for no apparent reason. I am running an aftermarket header/catback, and the wideband was installed in the downpipe. I guess it's possible the OEM 02 sensor may have found a better ground through the wiring of the wideband sensor (since it is directly wired to ground through the controller box). I don't know if it's a possibility but I can't help but wonder if this could've happened, thus causing a bigger current than the device was meant for and eventually ruining it.

I guess it's hard to know since I don't know whether or not this could provide a ground for the OEM sensor (depends on the wideband sensor design).

But maybe the failure wasn't so random as I thought haha. When I get another one I will test the ground wire with now power to the wideband but power to OEM and see what I can find out! Any ideas on the possibility of this?

Yeah, I think some of us did something that caused this during the install..
I used the SSAC gaskets and wondered if I should have used the OEM gasket. As others with the OEM gasket seem to not lost gas mileage. I also lost some low-end power as well. But, my old downpipe had cracks and leaks.



Danja, you're back!! Hows you car??

The wideband should have its own ground but if it was using the header/downpipe as the ground, maybe its the reason for eventual failure. Most people are only concerned with the power side of a circuit; meaning "Only concerned with the quality of the power side". I have learned from electronics experience (with lots of failures along the way) that the ground side quality must EQUAL the power side. Without the balance, the circuit life is shortened tremediously.

As for the O2 sensor using ground, Im not sure if thats possible. Only if the 2 sensors were directly connected or on the same circuit.

Haha, thanks man. It's better than it was but still not as good as before. there are pics over in the OT section on my thread. What I meant was that the wideband sensor, which is also metal contacted to the DP, is grounded through a wire that goes through the controller, not to the downpipe.

But, if the OEM 02 sensor was grounded to the mani/downpipe, is it possible that the wideband sensor/module provided a better ground for the OEM sensor's current (through the DP too) because it's wired straight to the chassis, thus causing excess current to flow through the control unit to ground?

Or is it more likely that because it has its own ground wire, the threading that touches the DP (on the wideband sensor) does not have any connections with the sensor wires itself (and then the above theory would not work)?

I can test this sometime after I get the new module.