# Should i just change the knock sensor? **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [October 20, 2007, 1:11am UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191 "2007-10-20T01:11:48Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![itnenaer](https://avatars.discourse-cdn.com/v4/letter/i/77aa72/32.png) [@itnenaer](https://community.cartalk.com/u/itnenaer)\ **Post date:** [October 20, 2007, 1:11am UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/1 "2007-10-20T01:11:48Z")
hi, my maxima’s check engine came on and the code came up for my knock sensor… P0325… my question is, should i change the sensor or is there something that caused the sensor to go bad? there is slight pinging…but it passed my emissions… the plugs were changed last year… ---
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [October 20, 2007, 4:00am UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/2 "2007-10-20T04:00:11Z")
Any part on any car can go bad and there may not be a particular reason for it. It’s electrical, so stuff happens. You can either just replace it and hope or follow the diagnostic steps in a decent manual and verify the knock sensor is the problem. The code is a circuit malfunction, not necessarily a bad sensor. If pinging continues after this is repaired then you should inspect the EGR system. ---
**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\ **Post date:** [October 20, 2007, 1:52pm UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/3 "2007-10-20T13:52:21Z")
If you are using lower than recommended octane gasoline (by the car maker, not Joe Blow), that could be the reason for the ping. The engine computer has the crankshaft position sensor and, maybe, a camshaft sensor to set the ignition timing and fuel flow where PING won’t, ordinarily, occur. With the gasoline octane too low, it may still ping after checking/repairing/replacing the knock sensor. ---
**Author:** ![SteveF](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/stevef/32/2_2.png) [@SteveF](https://community.cartalk.com/u/SteveF)\ **Post date:** [October 20, 2007, 1:55pm UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/4 "2007-10-20T13:55:11Z")
Just go ahead and change the knock sensor. It’s not all that expensive. Likely that will cure whatever ails and you can move on. If you still have a problem then you can review it further. ---
**Author:** ![Cougar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cougar/32/21348_2.png) [@Cougar](https://community.cartalk.com/u/Cougar)\ **Post date:** [October 20, 2007, 2:37pm UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/5 "2007-10-20T14:37:31Z")
Hold the phone Martha. Before replacing the sensor I would check things out further. Here is the definition of the code you gave. P0325 Generic Knock Sensor 1 Circuit (Bank 1) The code is for the sensor circuit, not the sensor itself. The ECU is complaining that it is seeing an unexpected signal on the sensor line that could be caused by a bad connection in the wiring too the sensor. Check the wiring for the sensor and make sure the connections are making good contact. If you can’t find a problem with the wiring then I would try a new sensor. ---
**Author:** ![femaletamale](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@femaletamale](https://community.cartalk.com/u/femaletamale)\ **Post date:** [October 20, 2007, 8:20pm UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/6 "2007-10-20T20:20:13Z")
I replaced the knock sensor when the check engine light came on and the code was read. It cost $250.00 plus labor, and after about 10 miles, the check engine light came back on. I wouldn’t make this change until I knew for sure. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [October 20, 2007, 10:14pm UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/7 "2007-10-20T22:14:07Z")
You can check for a bad knock sensor if you have a timing light. Hook up the timing light. And if there are no timing marks on the crankshaft pulley, just make several marks around the diameter of the pulley with a piece of chaulk. Get the engine running and up to operating temperature. While pointing the timing light at the marks on the pulley, take a wrench and tap on the engine block near the knock sensor. If it’s working, you should see the marks on the pulley change position with the timing light. If the marks don’t move when doing this, the knock sensor is probably defective. Tester ---
**Author:** ![markmast](https://avatars.discourse-cdn.com/v4/letter/m/4af34b/32.png) [@markmast](https://community.cartalk.com/u/markmast)\ **Post date:** [October 20, 2007, 11:45pm UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/8 "2007-10-20T23:45:35Z")
The knock sensor on the Maxima is known to fail for no reason after 6-7 years. I have replaced them on 96 and 98 Maxima’s. By the way, the Nissan shop manual for the cars I worked on calls for removal of the intake manifold to get to the sensor. You can get to the sensor without removing the manifold with a swivel joint socket and a long ratchet extension. If you need more information on this, post back. ---
**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\ **Post date:** [October 21, 2007, 12:29am UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/9 "2007-10-21T00:29:52Z")
Auto Zone auto parts web site lists the KNOCK SENSOR for only $179. So, if only $179 is pocket change, …change the knock sensor. ---
**Author:** ![itnenaer](https://avatars.discourse-cdn.com/v4/letter/i/77aa72/32.png) [@itnenaer](https://community.cartalk.com/u/itnenaer)\ **Post date:** [October 22, 2007, 1:05am UTC](https://community.cartalk.com/t/should-i-just-change-the-knock-sensor/6191/10 "2007-10-22T01:05:34Z")
i actually found one for way less on ebay…new and all… on a side note, i have purchased other parts from ebay (engine mount, radiator) and so far so good…