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Wiring up an LC1

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Old 12-12-2007, 03:54 PM
  #81  
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I think the hole Abe is talking about is the one what's his name used in a writeup. http://www.lightweightmiata.com/wbo2/wbo2.htm
I've got a 92 and my car doesn't have that hole.

Edit: Well seeing how Abe responded before me, here is another hole you can use
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Old 12-12-2007, 04:26 PM
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Originally Posted by AbeFM

Why would you keep the OEM sensor? Ok, $50 for the simulator is a bit spendy, but I figure instead of continually buying new sensors, I could buy that once, and it's worked out for me. Of course, as soon as you upgrade to a high-flow (or hollow) cat, the computer will throw CEL lights and it will be all that sensors fault.

Personally, I'd say with an aftermarket ECU you might as well scrap the whole O2 monitoring set up, and if you're not going to, I'd get the WB to share a signal with your OEM computer, and use an O2Sim to avoid the CEL. It comes out clean and when it's done you'll never need to do it again. If I was smart, I'd sell you mine. :-)
Why would I continually buy new sensors? As far as I understand the NB sensors dont have a problem with the added heat of the turbo.

I also thought that with a high flow cat the secondary sensor was fine as well? I know arkmage is emulating the precat signal, and kept his post cat sensor in the pipe and he is fine. I also know Cjernigan has an NB and he has both sensors in his pipes and he is fine too. Just dont know if either of them are using a high flow cat.

Where would I buy the o2sim anyway, and is it only for the post cat signal, or can it do both?

edit: last time I took my drivers seat out, I didnt see that hole for the secondary o2.
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Old 12-12-2007, 04:34 PM
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My rear O2 sensor is taped up under my car. When i bought the car it had 2.5" exhaust with no cat, just a cheap generic muffler. Instead of putting the O2 back in the pipe they just taped it up. I do deal with a CEL because of it.
I need an O2 simulator. Anything to get rid of the CEL. The O2 simulators only emulate the rear O2. Thats only because the stock ECU needs to see a leaner reading on the rear O2 than the front. Might not need to be much leaner, but that's how it's supposed to work.
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Old 12-12-2007, 04:37 PM
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Oh, so you do get a CEL. Why dont you just weld in a bung for less?
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Old 12-12-2007, 04:41 PM
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Originally Posted by Saml01
Oh, so you do get a CEL. Why dont you just weld in a bung for less?
I might but it would be nice to just take it out and not worry about it. The sensor might actually still be good. Hard to say though.
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Old 12-12-2007, 04:49 PM
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If the rear o2 just looks for a AFR variance, why not just throw a resistor between the signal off the front and the rear one, that would kinda do the same thing, and be linear.
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Old 12-12-2007, 08:25 PM
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The main thing about the rear O2, is it causes issues by reporting it's not present, or not working right. And of course, when it IS present and working right, then it bitches your cat isn't working right. It's a pain in the *** and it's only job is to BE a pain in the ***. :-) If you commute a lot, I'm all for having a cat and working smog equipment, why pollute if you don't need to. But for low mileage short use cars, it's just a CEL you have to deal with. I guess it serves you right for killing spotted owls.

Originally Posted by Saml01
Why would I continually buy new sensors? As far as I understand the NB sensors dont have a problem with the added heat of the turbo.

I also thought that with a high flow cat the secondary sensor was fine as well? I know arkmage is emulating the precat signal, and kept his post cat sensor in the pipe and he is fine. I also know Cjernigan has an NB and he has both sensors in his pipes and he is fine too. Just dont know if either of them are using a high flow cat.
You buy new sensors as old ones go bad. They DO do it, not often, but it's a continuing expense.

Different cars measure things different. My earliest idea was to put a resistored line off the front sensor, but it wants to see a time-lagged varying signal, even going up while the front goes down. The sim has a delay circuit in it. You could probably build something, but I don't know how. :-)


Originally Posted by Saml01
Where would I buy the o2sim anyway, and is it only for the post cat signal, or can it do both?

edit: last time I took my drivers seat out, I didnt see that hole for the secondary o2.
My car is a '00, I can't say what hole other people have. It's under the carpet though.
I got the sim from Baker Electronics, I think. Check my pictures, it's written on the device, along with my notes for hooking it up right. I guess I won't need mine, I just haven't gotten ok yet with selling off all my stuff - not that I'm going back but...

Originally Posted by Saml01
If the rear o2 just looks for a AFR variance, why not just throw a resistor between the signal off the front and the rear one, that would kinda do the same thing, and be linear.
yeah, that doesn't work. Many cars just want a resistor, most just need a time varying signal. But the Miata is blessed with uberanal
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Old 12-13-2007, 12:15 PM
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BakerElectronix yanked production of the o2 simulators.

They link to competitors that have em.
http://www.o2simulator.com/index.php...7cd617ffce866e


I think im going to pick up one of those 50 ohm 10 watt resistors Joe mentioned and wire it up with the LC1 to kill the CEL. Might as well kill problems as they crop up to keep the guess work down in the end.

If I understand correctly, all the ECU cares about is seeing a voltage drop relative to its output to know that there is a heater present?

Last edited by Saml01; 12-13-2007 at 12:34 PM.
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Old 12-13-2007, 01:48 PM
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Depends on the car. By all reports, you need to see a time delayed signal (the cat has a lagtime), but I would just try it. Its easy and cheap.

Here's a question:
why don't you pull your CEL? What is it doing for you?

A "helpful" previous owner pulled the airbag light out of my dash, and I'll admit, it never bugs me. :-)

<edit> Wow, a group buy of 5 is $30 each? Jesus, I think you guys should just get a batch and stop worrying.
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Old 12-13-2007, 02:00 PM
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I cant pull the CEL, NY requires inspections every year. My car is an OBD2, if I plug it into the computer and it throws a code I wont be passing inspection.

On the plus side. An O2 sim is cheaper then a high flow cat, thats for damn sure. Ill cross that bridge when I get there though. I am also curious why a high flow cat will mess with the second sensor, as long as the AFR is different it should be fine, I assume it changes AFR.

I wouldnt mind getting in on a group buy for an O2 sim though.

Edit: better question. How does O2Sim know what voltage to put out, does it need input from the first O2?

Last edited by Saml01; 12-13-2007 at 02:21 PM.
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Old 12-13-2007, 02:27 PM
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Originally Posted by Saml01
I cant pull the CEL, NY requires inspections every year. My car is an OBD2, if I plug it into the computer and it throws a code I wont be passing inspection.

On the plus side. An O2 sim is cheaper then a high flow cat, thats for damn sure. Ill cross that bridge when I get there though. I am also curious why a high flow cat will mess with the second sensor, as long as the AFR is different it should be fine, I assume it changes AFR.

I wouldnt mind getting in on a group buy for an O2 sim though.

Edit: better question. How does O2Sim know what voltage to put out, does it need input from the first O2?
This is the thing: The rear O2 sensor's only purpose in life (no, they didn't put it in just to make the car weigh more) is to determine if the factory catalytic converter is doing it's job.

When you put in a race cat, remove the cat, or have an old cat, the rear O2's job is to tell you "something's wrong, go buy another factory cat (or another rear O2 sensor)".

The O2 sim I used just puts out some widely acceptable voltage. Remember, NB O2 does not put out a voltage so much as a digital signal, it's essentially a PWM source. :-) The computer sees 1 second of "high" and 3 seconds of "low" and figures you're lean. Or close enough for this soundbyte. :-)

But the sim is cheaper than a new O2, so there's not a lot of reason not to do it. Then keep your secondary as a spare for your primary O2.
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Old 12-13-2007, 02:47 PM
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Youre the man, AbeFM. Thanks for the education.

Now to just convince three more people to get O2Sims, I think Cjernigan would be in on it.
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Old 12-28-2007, 02:17 AM
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Originally Posted by Saml01
Where can I connect the heater ground. I probably shouldnt put it on MS grounds, can I just attach it to the chassis next to the MS or do I have to run it back to the throttle body?
...
Thats all. My main concern is power for it.
Oddly, the manual says to ground both heater and signal the the SAME location. It doesn't make much sense to me - especially since why did they put two wires then?

I'm kinda tempted to follow their directions, but I kinda thing bolting the heater ground somewhere else is a good thing.

Originally Posted by LC-1 Manual
4. Connect the RED wire to a switched 12V source in your car. A switched 12V source
goes on as soon as the ignition on the car is on. Make sure the connection is fused with a
minimum fuse size of 5A.
5. The BLUE and WHITE wires should all be grounded to the same ground source and
although these grounds are of the same source, the BLUE wire should be wired separate
from the WHITE wire to avoid analog ground noise. Optimally, these (and any other MTS
device ground) will be soldered to the same lug, and connected to a single point. When this
isn’t possible, connect each one to a separate lug, and attach in close proximity. Multiple
lugs on the same bolt is not optimal, and can result in unwanted signal “noise.” When
possible, soldering is always better than crimping.
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Old 12-28-2007, 09:10 AM
  #94  
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Bolt it all, and I mean all things LC1 related to the same lug. I already did enough experimentation with their grounds, trust me.
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Old 12-28-2007, 12:18 PM
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weird, but good to know. The less 'experimentation' the better.
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Old 12-28-2007, 12:43 PM
  #96  
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Mine's got 3 grounds, these are the Innovate recommendations for mine in a nutshell
heater -- go to motor, locate near system ground, but keep separate
system -- locate near hater ground, but keep separate
analog reference -- locate to ecu sensor ground

I think that average joe user couldn't handle following all 3 steps, Innovate's tech support was becoming frustrated with the calls and complaints, so they said F-it. Get less for less.
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Old 01-06-2008, 08:41 PM
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Oh, that would be awesome. I want a signal ground.


So, like, here's my issue. I plug everything in, turn the key and.... madness ensues! Relays clicking, injectors firing, etc etc. Totally apeshit. After a few seconds, it dies down. But I don't like it.


I unhook the power to the innovative, everything's cool, like fonzie. A bit more dinking around, and basically, if I ground the two lines on the frame (metal bits under the dash) everything is fine. If I ground it on the DB-37, it has a **** fit.

So like, what do I do? My guess is poor grounds overall and it needs looking at, but I don't see why, everything should be solid and I have like 4 huge wires for ground. I really want to ground the heater return to the frame and the signal at the computer, but I guess it's a no-no, so what do I do?
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Old 01-06-2008, 09:40 PM
  #98  
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Youre not supposed to run the sensor and heater grounds to the the MS without bolting it to the engine as well.

Run one of the MS sensor grounds to a ground running off the engine, then run all the other grounds to the same spot. Never run grounds to the MS without dumping them on the engine as well.
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Old 01-06-2008, 10:28 PM
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weird. But sounds plenty reasonable. And I'd love to get some mass between the ground and my car. Just have to run a ground stap out.
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