O2 sensor CEL keeps coming back!!!!

Asura_SI

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Can anyone help me figure out why on my 2018 Civic SI keep getting CEL regarding O2 sensor? The code p0134 keeps popping up. I got an Invidia exhaust, PRL Front and Downpipe, oil catch can, AEM short ram intake, and Ktuner (Tuned by Derek Robinson).

This CEL only started showing up after the Front and Downpipe and the tune. I kept clearing it since I didn't think it was much of a big deal. Now I went to get my car inspection and couldn't pass because of OBD Readiness Monitor Results. Catalyst, Evaporators System, Oxygen Sensor, and EGR and/or VVT System showed as not ready. It only reads as Ready after 40ish miles except for EGR and/or VVT System.

I talked to Derek Robinson and he recommended to change the O2 sensors so I did and the p0134 code still comes up but less. Also, I put my car back into factory tune and driving it 300-400 miles as per recommendation of my friend who is doing my car inspection.

Anyone got a clue on why this happens and the possible fix?

Honda Civic 10th gen O2 sensor CEL keeps coming back!!!! IMG_1613


Honda Civic 10th gen O2 sensor CEL keeps coming back!!!! IMG_1614
 

jayy_swish

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That code can came up for a few things O2, exhaust leak, intake leaks, faulty injector. Since the O2 sensor was replaced, first check your O2 connection make sure it doesn’t have any rodent chew marks or it’s showing wires somewhere. Get some soaping water and spray it around your exhaust where they screw into one another if you see if bubbles I would Re-tighten. Re-spray with soapy water then replace the gasket. If still doesn’t fix the issue then it’s a bad exhaust pipe. Next recheck all your connections to your intake and relighted everything. My guess it’s your exhaust since it started happening after the install correct ?
 
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Asura_SI

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That code can came up for a few things O2, exhaust leak, intake leaks, faulty injector. Since the O2 sensor was replaced, first check your O2 connection make sure it doesn’t have any rodent chew marks or it’s showing wires somewhere. Get some soaping water and spray it around your exhaust where they screw into one another if you see if bubbles I would Re-tighten. Re-spray with soapy water then replace the gasket. If still doesn’t fix the issue then it’s a bad exhaust pipe. Next recheck all your connections to your intake and relighted everything. My guess it’s your exhaust since it started happening after the install correct ?
I apologize, the code is P0139, not P0134. But yes it did happen after the install. I will lift my car today and try this out.
 

jayy_swish

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I apologize, the code is P0139, not P0134. But yes it did happen after the install. I will lift my car today and try this out.
If that’s the code it’s even easier o2 or exhaust leak. I’m assuming secondary o2 is off in the tune? If not turn it off problem solved.. CEL is gone. If it’s already off and the CEL is still on then it’s an exhaust leak
 


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Asura_SI

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If that’s the code it’s even easier o2 or exhaust leak. I’m assuming secondary o2 is off in the tune? If not turn it off problem solved.. CEL is gone. If it’s already off and the CEL is still on then it’s an exhaust leak
If this is the case and you are correct, are you implying to change the gasket? Or just tighten the bolts?
 

jayy_swish

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If this is the case and you are correct, are you implying to change the gasket? Or just tighten the bolts?
Mix about a ounce of dish soap (the more soap the more chances of more pronounced bubbles) and water in a spray bottle. Turn the car on and spray the soapy water and look for the bubbles. Spray the connection points first, since those are the more common leak points, and see if there’s any bubbles. If there’s bubbles and the gaskets were new supplied with the dp/fp then retighten the bolts. Re-spray with soapy water and check for more bubbles, if there is still more bubbles just replace gasket with a Honda OEM gasket unless it requires a different style gaskets. If you spray all the connection points and there’s no bubbles anywhere then you might have a fault welded dp/fp or a crack. So you begin spraying the whole piece itself, drench it and check for bubbles. If you see any on the welds or there’s a crack take video/picture proof. Contact the manufacturer and see if you can get a new one
 
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Asura_SI

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Mix about a ounce of dish soap (the more soap the more chances of more pronounced bubbles) and water in a spray bottle. Turn the car on and spray the soapy water and look for the bubbles. Spray the connection points first, since those are the more common leak points, and see if there’s any bubbles. If there’s bubbles and the gaskets were new supplied with the dp/fp then retighten the bolts. Re-spray with soapy water and check for more bubbles, if there is still more bubbles just replace gasket with a Honda OEM gasket unless it requires a different style gaskets. If you spray all the connection points and there’s no bubbles anywhere then you might have a fault welded dp/fp or a crack. So you begin spraying the whole piece itself, drench it and check for bubbles. If you see any on the welds or there’s a crack take video/picture proof. Contact the manufacturer and see if you can get a new one
So I just checked it. sprayed everywhere and found no leaks. not sure where to go from here. Here is a video I took of the readings of the O2 sensor
 

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So I just checked it. sprayed everywhere and found no leaks. not sure where to go from here. Here is a video I took of the readings of the O2 sensor
Next move for me would be to add a defouler to the o2 sensor if it does not have one already. Also double check your tune settings and make sure the settings are set up so that your secondary o2 sensor is turned off
 

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For P0139, you want to turn off the o2 sensor slow response in Ktuner.
 


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Asura_SI

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Found a solution for it!!!! So PRL sent me a defouler and it was too long so I ordered a shorter one and the code went away after 10 mins of driving. No need to mess with ktuner!
 

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my guess would be the AEM intake is the culprit.
It's your down pipe 100%. I and the same thing happen. The code kept popping up no matter what I did bunch of the followers even scanned nothing... Few months after I took it to a tuner to get the car tuned and the tuner got rid of it sorry I have no idea what he did. All I know is that he got rid of it in the k-tuner app. Just take it to a runner, May as well dine on the car while you're there too. Lol
 

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Found a solution for it!!!! So PRL sent me a defouler and it was too long so I ordered a shorter one and the code went away after 10 mins of driving. No need to mess with ktuner!
Did you have to remove the downpipe to switch out the defoulers? Or is there a way to do it without removing it?
 
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Asura_SI

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Did you have to remove the downpipe to switch out the defoulers? Or is there a way to do it without removing it?
sooooo I was able to remove the defiler without removing the PRL downpipe. I had so saw it in half in order to remove the defouler. Took me about 20 mins
 

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Found a solution for it!!!! So PRL sent me a defouler and it was too long so I ordered a shorter one and the code went away after 10 mins of driving. No need to mess with ktuner!
Can you please give the link to the one you ordered :)
Sponsored

 


 


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