# Knock Sensor

**URL:** <https://community.cartalk.com/t/knock-sensor/23339>\
**Category:** Maintenance/Repairs\
**Created:** [December 13, 2008, 2:57am UTC](https://community.cartalk.com/t/knock-sensor/23339 "2008-12-13T02:57:44Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![arlotta5](https://avatars.discourse-cdn.com/v4/letter/a/a88e4f/32.png) [@arlotta5](https://community.cartalk.com/u/arlotta5)\
**Post date:** [December 13, 2008, 2:57am UTC](https://community.cartalk.com/t/knock-sensor/23339/1 "2008-12-13T02:57:44Z")

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I have a 1996 cavalier with a knock sensor code coming up on the check engine light. Put in a new sensor still getting the code . put in new plugs and wires still no luck. Car runs great anyone have any ideas to fix this problem.

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**Author:** ![oldschool](https://avatars.discourse-cdn.com/v4/letter/o/e19adc/32.png) [@oldschool](https://community.cartalk.com/u/oldschool)\
**Post date:** [December 13, 2008, 3:40am UTC](https://community.cartalk.com/t/knock-sensor/23339/2 "2008-12-13T03:40:42Z")

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This may be a case where some “snapshots” (with a scan tool) will be needed to identify whats going on when the code is generated,or it could be a wiring failure,corrosion,rodent damage? I have seen all three with the Caviler.

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [December 13, 2008, 3:41am UTC](https://community.cartalk.com/t/knock-sensor/23339/3 "2008-12-13T03:41:12Z")

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Exactly what code or codes is it? Getting any rattling on acceleration with a warmed up engine?

Keep in mind that if you have a specific knock sensor code that does not necessarily mean the knock sensor itself is bad; only that a problem exists in that circuit. It could be the wire harness, wire connector, ECM fault, etc.

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**Author:** ![pleasedodgevan](https://avatars.discourse-cdn.com/v4/letter/p/51bf81/32.png) [@pleasedodgevan](https://community.cartalk.com/u/pleasedodgevan)\
**Post date:** [December 13, 2008, 4:13am UTC](https://community.cartalk.com/t/knock-sensor/23339/4 "2008-12-13T04:13:52Z")

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Some knock sensor problems happen when there is a tapping sound that is interpreted as a knock. If you have a bad lifter or a loose wrist pin (on a piston) or a rumbling bearing on an accessory, you could also notice a loss of performance due to the timing being retarded when the knock sensor tries to do its job.

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**Author:** ![arlotta5](https://avatars.discourse-cdn.com/v4/letter/a/a88e4f/32.png) [@arlotta5](https://community.cartalk.com/u/arlotta5)\
**Post date:** [December 13, 2008, 4:51am UTC](https://community.cartalk.com/t/knock-sensor/23339/5 "2008-12-13T04:51:24Z")

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po325 knock sensor 1  
circuit malfunction  
bank 1 or sensor 1

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**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\
**Post date:** [December 13, 2008, 5:10am UTC](https://community.cartalk.com/t/knock-sensor/23339/6 "2008-12-13T05:10:37Z")

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If you hit speed bumps, or drive on a bumpy road, you might set the knock sensor code.