P0325 Knock Sensor 1 Circuit and intermittent CEL

[tazorak]

Hi all,

 

I have a 98 Impreza Outback Sport that's had an intermittent check engine light. I've pulled the code multiple times and I've had the same code pop up every time P0325 (generic) - Knock Sensor 1 Circuit (Bank 1). I've read around about it a bit and seems like a fairy simple fix but I'm no mechanic so it's a bit out of my league in regards to doing it myself.

 

The car drives relatively normal, however sometimes has a little power loss in the low-end. 

 

I'm wondering how simple it is to swap out the knock sensor? And if I don't replace it soon, what are the ramifications of doing so? Can having a bad knock sensor break other things? I know that the CEL will reduce gas mileage etc and makes the vehicle run slightly different.

 

Thank you and I look forward to hearing opinions and thoughts.

 

 

[Fairtax4me]

Not out of your league if you have a basic tool set.

 

Search here for my knock sensor 101 thread and it covers all the basics you need to know about finding and replacing it.

[tazorak]

Thanks for the response. Do you know what kind of ramifications there are for not immediately replacing the sensor?

[fishy]

Thanks for the response. Do you know what kind of ramifications there are for not immediately replacing the sensor?

 

The knock sensor helps the ECU control ignition timing so if that gets out of whack you could hear the motor pinging  (which can be damaging if you have a lot of it) or more likely as you have described a loss of power in certain parts of the rev range. Also my understanding is that when the CEL comes on the ECU is going to pull timing anyway to keep the engine safe. It's not awfully likely to cause serious damage but it's a fairly quick fix and can be done very cheaply. Fairtax's thread has all the info you would need. 

 

I can't remember if I added my video to that thread or not but I did a video about knock sensor replacement on my 98 Impreza:

 

[Fairtax4me]

Thanks for the response. Do you know what kind of ramifications there are for not immediately replacing the sensor?

All covered in my 101 thread.

[idosubaru]

it's one bolt and super easy, it's easier than an oil change.  

buy a cheap EBAY sensor and pay someone to install it for you if you can't.   it's so easy (one bolt) anyone with a set of tools would gladly do it for a few bucks. 

[Bushwick]

While "easy", it not's the easiest thing to get to, and it must be repositioned in a specific manner so it seats correctly. If you still get codes after replacing (pull battery cable and reset) then it's most likely not seated correctly.