Codes P0506 and P0325?

2003 HONDA ACCORD
192,500 MILES • 2.4L • 4 CYL • 2WD • AUTOMATIC
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MAKAILA ROSE
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Hi! I have two codes showing. The first code for the knock sensor P0325 has been there for months and no matter what part I change it stays there. I replaced the knock and circuit sensor with brand new parts. Now, there happens to be a new code P0506 Idle Air Control System RPM Lower Than Expected. For reference, I have replaced my throttle body not even a year ago and the sensor that goes on it. I don’t know if perhaps the throttle body has gone bad and I need to purchase a higher valued one, but I need help knowing how to fix this code. my father is my Mechanic, but he is older now and only knows how to figure out how to fix so much. He believes I should get a new throttle body with a sensor on it. What do you think? Thank you. :)
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Mar 23, 2025 at 3:08 PM
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Hello Makaila,

Can I ask if when the engine is running does it have any unusual noises, can you please upload a short video of the engine running? If the engine is making a knocking sound it, you will get this code.

Please go over this guide to help:

https://www.2carpros.com/articles/how-a-knock-sensor-works

Code P0506 - Idle Air Control System RPM Lower Than Expected

Code P0325 - Knock Sensor Circuit Malfunction

Please start a new thread for the P0325 code as we only handle one problem per post.

https://www.2carpros.com/questions/new

Please go over the guide and get back to me with a video if you can.
Mar 25, 2025 at 2:05 PM