The car is a 88 crx hf with a b16a.

I have got code 23 since I bought the car so I go to try to find my knock sensor and couldnt find it for the longest cuz nothing was sticking out and not a lot of room to see and now I have finally found where there is supposed to be a knock sensor and this is what it looks like. The car runs fine, idles fine, v tec works.







Can anyone tell me why its like this? could it be the previous owner didnt want the knock sensor and used some ECU that doesnt need the knock sensor?

Heres a pick of the ECU, I dont know how to tell what ECU it is.

 

there should be a sticker on the side of it saying which ecu it is. what motor are you using?

 

Looks like the top of the sensor, all the plastic part and metal prong of the connector, have been sheered off.
A good knock sensor looks like this



Look on the side of your ECU for the sticker that looks like a Bar Code.
The image below is a JDM B16 ECU which is designated by the "PR3-J01"
I am thinking you probably have a PR3 as well.


You can open up the ECU to check it out a little more.
The knock sensor ECUs have a knock board in them.
If that board isn't in there, then you have no use for a knock sensor.
However, if you DO have the knock board then you should get a working sensor and wire it up.
While you are driving around with the CEL on, your ECU is retarding your ignition advance a few degrees.
With the knock sensor fixed, you should see some increase in performance and have a bit of a safeguard for your motor if you ever get internal detonation.
(After you get it hooked up, check your timing)

 

Looks like the knock sensor is broken. Get a new one. The reason you are throwing code 23 is because you don't have your knock sensor connected. As for the ECU, you either have a PR3 or PW0. Both were used for the OBD0 B16A and both require the knock sensor. So you do have the right ECU.

 

Ok So I checked out the ECU sticker and it is PW0 and it does have the knock sensor board. I have a Thread close to this one that says "video - loose wire found behind block" yada yada. IF anyone of you can check out that thread and maybe tell me if u think that is the knock sensor wire and connector. I'm gonna go to autozone and look at a knock sensor so i can maybe make some guestimations. Do I need to pull out what is left of the knock sensor in the block or if i get a new one i can just stick it in those holes? For some reason I don't get a CEL when I drive at night....IDK it weird. Thanks all for help.

 

i went ahead and bought a new knock sensor. Darn I wish it wasnt $109! Ive put over a grand in this damn car since I bought it and thought I was completely done with putting money into it! lol. Is all worth it tho! Tomorrow Im gonna go ahead and try to get the old senor out without having to remove anything to get to it. Wish me luck. again thanks for all the help posters.

 

how did you get yours out. its broke off on my h22a and idk what to do?