Engine popping sound from exhaust

2009 MAZDA SPEED3
180,000 MILES • 2.3L • 4 CYL • 2WD • MANUAL
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CHAINES291
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Hello, I have a engine popping sound from my exhaust. It sounds like mini misfires but I have no CEL. I have a access-port to monitor engine performance and my knock retard from my knock sensor is really high. Is it possible my knock sensor is picking up the mini misfires? Attached is a video where you can hear the sounds. The muffler is broke off so it is even more noticeable. Thanks
Video (Click to enlarge)
Attached Media
Sep 11, 2018 at 8:22 PM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
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HI and thanks for using 2CarPros.com.

I listened to the noise. Are you sure something is not loose in the system? Often times the insides of the converter will come loose and make a noise similar to this.

Take a rubber mallet and tap on the converter to see if that is where the sound may be coming from. Any misfire should turn on the check engine light. That is why I am questioning what is happening.

Take a look at this link. Also, if the check engine light is on, let me know what codes you found.

https://www.2carpros.com/articles/bad-catalytic-converter-symptoms

Here is a link that describes how to check the catalytic converter:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter


Let me know.
Joe
Sep 15, 2018 at 7:21 PM
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CHAINES291
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I have a aftermarket down pipe that deleted the catalytic converter. So it is a just a pipe with the two o2 sensor on it. Upstream and down. I have no misfires colds. Only codes you have is for EGR delete and p2006 VTCS which the wire is broke for the sensor that tells it that is it is moving. Thanks for reply.
Sep 15, 2018 at 10:46 PM
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JACOBANDNICKOLAS
  • AUTOMOTIVE REPAIR CONTRIBUTOR
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Hi again,

Since the vehicle has been modified, that makes it more difficult. Are you sure the variable shutter tumble valve being closed is not causing your issue?
Sep 16, 2018 at 7:49 PM