ford aspire heated o2 sensor (upstream)

[rmoltis]

It's been a while since I drove the beast.

So I decided to take it for a drive today.

Let the car warm up

I turned the adjustable fuel pressure regulator back down to stock pressure.

And set the ignition timing a few degrees forward.

Then I went and drove around the city and on the freeway and whatnot.

So the stock upstream o2 sensor that I extended when I got the DAE header put on.
Turns out to be working fine with the ghetto extension.

I programmed a custom o2 sensor gauge into the scanguage that displays o2 voltage from .01v-.99v

Also had the loop status gauge on for reference.
But what I figured out was that at idle/part throttle and low rpm driving.
The voltage drops down to .05-.07v
And goes into open loop.

Meaning it doesn't stay warm enough to stay in closed loop at idle/part throttle/low rpms.

But if I give it wot or stay in a higher rpm it brings the voltages back into the .30v-.80v range
which is what it should be reading as usual.
And it puts it back into closed loop while there.

So I'm contemplating rigging up a heated o2 sensor.
That way it is better able to stay in closed loop at idle and part throttle.

Bad news is I have a brand new Denso upstream o2 sensor in the box that I've been saving that will be useless to me if I go through with the heated o2 sensor idea.
Maybe someone on here would be interested in buying it off me.

Anyways.
If I got the heated sensor.
How would I wire it up?
Just splice a stock connector to the signal wire and plug it into the harness
Then take the power wire and mount it to a source that turns on with the car and off with the car?

Where would be best location to run the power wire to for this?

And how to choose o2 sensor with compatible thread size and the heating element?

I only payed $34 for the brand new OEM Denso replacement I bought.
And I'd like to have a Denso heated sensor for a similar price if possible.

Any ideas/help would be appreciated.

And another thing.
it was a hot day outside today 80-90
and even still the sensor was cold enough to drop into open loop at idle and part throttle/low rpms.

So I can't imagine what would happen when winter rolls around if I don't upgrade.

when the car is in closed loop or wot this header definitely adds power all around.
I'm really loving it.

Once this heated sensor idea is done everything should work perfectly.
Plus I'm sure this will help others.

[rmoltis]

So I never got any replies for this thread and instead of starting a new thread I will just ask again.

When I install my heated o2 sensor.

Where do I splice the power wire into so that it turns on and off with the vehicles ignition?
I have a factory shop manual but i am bad with interpretting the electrical diagrams.

If anyone could help me with this it would be much appreciated thx.

[jason_]

Key off, poke around with a test light.

Make note.

Key on, poke around with a test light.

Make note.

Fuel pump relay might be convenient?

Sent from my rooted HTC Supersonic using Tapatalk 2 Pro

[TominMO]

1. If I got the heated sensor, how would I wire it up?
Just splice a stock connector to the signal wire and plug it into the harness.
Then take the power wire and mount it to a source that turns on with the car and off with the car?
Where would be best location to run the power wire to for this?

2. And how to choose o2 sensor with compatible thread size and the heating element?

1. A typical heated O2 sensor has four wires: one signal (to the ECU), one ground, and two power (to heat it).
Signal obviously gets spliced to the stock one-wire, so the ECU can see it.
Ground would best go to the engine, like a valve cover bolt.
The two power/heater wires can be spliced to any 12v source that is on only when running. Easy to find with a multimeter.

2. Almost all O2 sensors have the same 18mm thread; it's an industry standard. There is another kind that is attached by two 10mm bolts, and looks very different. You can't confuse them visually. The heating elements should basically all be the same, since they operate off a 12v signal.
This part # is the downstream O2 sensor for the 1996-97 Aspire: Denso 234-4209. This would be the universal one that requires splicing. $30 on Amazon.

http://www.amazon.com/Denso-234-4209-Oxygen-Sensor/dp/B000C5WCUE/ref=sr_1_1?s=automotive&ie=UTF8&qid=1379715490&sr=1-1&keywords=denso+2344209

(When you click on this link, you will see that it says it does not fit the Aspire. But that is because it is the one without the specific plug. Don't worry about it.)

[Pu241]

I programmed a custom o2 sensor gauge into the scanguage that displays o2 voltage from .01v-.99v

Also had the loop status gauge on for reference.
But what I figured out was that at idle/part throttle and low rpm driving.
The voltage drops down to .05-.07v
And goes into open loop.

Meaning it doesn't stay warm enough to stay in closed loop at idle/part throttle/low rpms.

But if I give it wot or stay in a higher rpm it brings the voltages back into the .30v-.80v range
which is what it should be reading as usual.
And it puts it back into closed loop while there.

Any chance that wrapping the header might retain enough heat to keep temps up?

[rmoltis]

I don't think wrapping the header would help.

Ive heard of people wrapping their header have them oxidize and rust faster than usual.

Also on the last day I drove the beast it was 90 degrees out.
And it wouldn't get out of closed loop unless I floored it or kept it at a higher rpm.

And when it hits the 0-3 degree mark it definitely wouldnt help.

So the quickest and most sure answer to this problem is a heated sensor.
Guranteed It will for sure heat up to temp every time and within 30 seconds .
And deliver accurate air fuel readings everytime.

So its just a matter of locating an ignition switched 12 volt source
that would supply enough voltage to run the o2 sensors heating element.
Without popping any fuses.
As well as not draining voltage when the car is turned off.

[getnpsi]

The escort GT that had the 1.9 non mazda engine is a factory header AND factory 3 wire o2 sensor. From what i remember its way downstream. I considered buying one and having it reflanged to the b8me at one time. MAybe it could be done to a b3/b6 as well...no one on here has done this sort of thing---easier to swap a whole engine with the aftermarket support you desire....anyway, late 1980s and early 1990s fords have 3 wire sensors, so there is not a circuit code if the element fails, they just fail and the signal to o2 still will read, albeit take longer to come up as its working like a single wire. That 4th wire is to tell the ecu (usually obd2)that the o2 has issues even if it can still send accurate a/f--which it would most likely with an iron manifold. Beware some o2 sensors are longer probe inside than others, ive seen some really shallow ones and some that stick out a lot, the newer ones thank goodness tend to be the shorter ones but that is dependant on the engine designers. Good to get a book out or rockauto and get visual, or hands on at autoparts store if they let you. If you are clumsy and drop a sensor it may not work, even pickier than a spark plug as its obvious you broke one if its broken.

I agree tho tom, some o2 sensors have a dedicated wire ground, some are using itself as the ground like a light bulb and other single wire temp sensors and so on

[TominMO]

And in some applications, if you buy a universal splice-type 4-wire sensor, the ground wire is not used.

[rmoltis]

I understand where the signal and ground wires go.

I'm just not sure which factory wire to splice into for a 12v source.
I know the installation won't be hard its just a matter of knowing which wire to use.

Also when I get a wideband installed down the road I would have them both spliced into this wire.

Unless there was some way to get them both their own dedicated 12v source through the fusebox???

[rmoltis]

I'm thinking of something like this.

It's called add a circuit.
It uses an existing fuse and creates a second fused circuit
with primary wire coming off of it to add an accessory.

I think it would be the easiest route.
Just a matter of figuring out and adding up current draw of o2 sensor + future wideband+wideband gauge.
This particular one supports up to 10amp fuses.

http://www.amazon.com/gp/aw/d/B0002BGELQ

[Pu241]

What about just getting a relay, much like for fog lights. Then you can tap into any circuit that goes live when your in the "on" position. It will handle the current and not the existing wiring.

[rmoltis]

So I went ahead and ordered the add a circuit.

I got 3 of them so I could add other things later if necessary.

It was 10.87 for all 3.

http://www.ebay.com/itm/150988998670?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

No wire splicing or hacking required.

Just plug and play and connect primary power wire to crimp connection.

Easily removeable if ever neccessary

I got one for heated narrowband o2.
One for future wideband.
And one for future expansions.

Seems like the easiest simplest fix.

[TominMO]

I'm thinking of something like this.

It's called add a circuit.
It uses an existing fuse and creates a second fused circuit
with primary wire coming off of it to add an accessory.

I think it would be the easiest route.
Just a matter of figuring out and adding up current draw of o2 sensor + future wideband+wideband gauge.
This particular one supports up to 10amp fuses.

http://www.amazon.com/gp/aw/d/B0002BGELQ

FYI, these add-a-circuit things can be found at McParts stores too. Advance has it for about $6, without fuses; the brand is Buss.

[getnpsi]

You could have gone into where the alternator is, so its only getting signal when it engine actually tuning, not just key on. I don't think that matters much however.