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Old 08-25-2016, 11:56 PM   #1
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Default Stock idle as 10.5 afr?

Just installed a wide band. The turbo was going in this weekend but now she idles at 10.5 where to look?
97 mx5
no rear o2
on start up it idles at 14-15 but after driving when coming back to idle it drops to 10 lowest I've seen is 9 car almost stalls
will take a video however the car ran fine before the wide band was installed.
at WOT AFR is 11-12 then 13 after ~4000
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Old 08-26-2016, 12:38 AM   #2
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Wha?
Are you running stock ECU? More info!
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Old 08-26-2016, 02:19 AM   #3
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where is the o2 sensor installed.
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Old 08-26-2016, 06:38 AM   #4
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cause effect.
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Old 08-26-2016, 08:59 AM   #5
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Quote:
Originally Posted by Braineack View Post
cause effect.
Yeh

"no rear o2"

So you removed the stock o2 sensor in favor of the wideband?

So basically, the stock ECU has no feedback now (no stock o2), so it can't go into closed loop mode. You're running in open loop, so it's super rich.

Edit: you can probably run your Wideband in Narrowband simulation mode (depending on the model) and fix this.

Last edited by Onyxyth; 08-26-2016 at 09:23 AM.
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Old 08-26-2016, 11:04 AM   #6
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What wideband do you haz?

Going with what Onyxyth mentioned, the MTX-L has a pretty brown wire you can use as a narrowband output to the stock ecu if programmed correctly.

http://www.innovatemotorsports.com/s...rint%201.2.pdf
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Old 08-26-2016, 11:08 AM   #7
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rear o2 isn't the oxygen sensor y'all are looking for
which still doesn't explain why OP fails so hard at posting a proper/comprehensive description of his setup and what's happening.
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Old 08-26-2016, 03:57 PM   #8
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Quote:
Originally Posted by 18psi View Post
rear o2 isn't the oxygen sensor y'all are looking for
which still doesn't explain why OP fails so hard at posting a proper/comprehensive description of his setup and what's happening.
Well, my thinking was "no rear o2" would imply he replaced his front (and only) o2 with the wideband - so it's stuck in open loop.
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Old 08-26-2016, 04:04 PM   #9
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plug in a scan tool and read the STFT and LTFT. It they are always 0 your in open loop. or you might have an OL/CL PID available.

I suspect if your 02 is disconnected it's reporting a lean condition and your STFT might read +25%, or whatever it's cap, is making the mixture very rich. There's no way in OL mode your fueling should be that far off unless you have some kind of sensor issue. Also, your car runs in OL with 0% STFT in warmup which would explain why it starts off near stoich. Also, at WOT it's in OL with STFT 0% and would explain why WOT fueling is okay.
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Old 08-26-2016, 06:50 PM   #10
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ok boys figured it out! after checking cels at work and sensors coolant temp, tps and my timing went to look over my wiring and found where i spliced into for o2 readings in the stock ecu came lose and was grounding itself on the block it was dark and late should have double checked my wiring.
now if only i could find that o2 signal modifier i missed placed???

Last edited by Bound1ess; 08-26-2016 at 06:51 PM. Reason: spelling
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Old 08-26-2016, 06:53 PM   #11
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which also explained why it was intermittent i moved front sensor to rear so only cel is evap witch is plugged and removed
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