Trying to pass inspection and failing. Code P0139

NoTorque

Active Member
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2015 Civic Si with a rv6 catted down pipe

So I turned on my secondary o2 sensor but kept everything else on my tune the same and was going to get inspected but after driving around for a short while I got code P0139.


I'm reading that means the secondary o2 sensor is possibly bad?

I can't clear the code.

I've had the o2 sensor off for a year now using a tune by vit.

Am I screwed or what can I do?
 

NoTorque

Active Member
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In flashpro you had it disabled before? If not:

Open the calibration tab.... then click on closed loop..... and then uncheck "secondary O2 sensor enabled"
I checked it because I thought you had to have it enabled to pass inspection?
 

webby

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I guess it may depend on where you live or what your inspection involves? What state is your inspection in? Do you know what's involved with the inspection? Visual? Run it on a dyno type machine to test emission levels?
 

stilletto

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You can run an emissions readiness test with the OBDII Torque App. Dunno where you're located, but Illinois is just OBDII.

Sent from my SM-G930T using Tapatalk
 

NoTorque

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You can run an emissions readiness test with the OBDII Torque App. Dunno where you're located, but Illinois is just OBDII.

Sent from my SM-G930T using Tapatalk
OK I'll check out that app. I think NC is obd2 only as well.

Does that mean I can get away with having the secondary o2 off?
 

NoTorque

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@Tony An or someone else from NC may know what's involved. Do they require new cars to be tested in NC? A lot of states exempt cars up to like 3yrs or whatever.
NC requires it every year even if new. I'm just trying to figure out if I can get it through with a catted down pipe somehow and if this code means I need to replace my o2 sensor.

Edit: I'm pretty sure the o2 sensor is fine. It's just reading high from a "defective" catalytic converter. I'm surprised Flashpro doesn't hide the code.
 
Last edited:

Nomar06

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If you have a cat on the down pipe and the O2 sensor isn't throwing a code, then you should be good to go.

They do visual inspections as well as the sniffer on the tail pipe.
 

NoTorque

Active Member
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If you have a cat on the down pipe and the O2 sensor isn't throwing a code, then you should be good to go.

They do visual inspections as well as the sniffer on the tail pipe.
It is throwing the p0139 code [emoji27] even with the defouler

I just flashed back to stock.

Am I screwed?
 

NoTorque

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You need a shop to clear the code. It may return though if you're saying the cat is "defective"? Why is the cat defective?
I don't think it's defective, it's just probably giving an out of range response
 

NoTorque

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Back to stock tune with defouler and o2 on it still throws the code.

I'm surprised that no one has passed with a down pipe
 
Last edited:

webby

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If you're on the stock downpipe, why are you running the defouler?

clear your code in flashpro, put the stock downpipe on & no defouler. There are plenty of people who've passed inspections with aftermarket downpipes, but you said you're throwing a code because "the cat is defective".
 

NoTorque

Active Member
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If you're on the stock downpipe, why are you running the defouler?

clear your code in flashpro, put the stock downpipe on & no defouler.
Rv6 catted down pipe. So I'll pass visual, just wondering about the odb scan test.

I was trying to avoid putting the stock downpipe on and off every year.
 

NoTorque

Active Member
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There are plenty of people who've passed inspections with aftermarket downpipes, but you said you're throwing a code because "the cat is defective".
It throws a code with the secondary o2 sensor on, even with a defouler in place.

So you're saying you can pass even with the secondary o2 not ready (off)?
 
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