Does anyone know what size socket will fit the JDM H22 knock sensor? I can't find the spec in the Helms and the local auto parts store's 1" and 1-1/16" oil pressure sensor socket didn't fit.

I recently did a datalog of the oem knock sensor with a Hondata s300 and the stupid thing picked up knock activities when lightly blipping the throttle in neutral to 1200 rpm! It also registers knocks and retards timing during very light throttle input durng cruising. This results in sudden lost of power or sudden slight hesitation. No hesitation when disabling the knock sensor. Therefore, I want to swap out the oem sensor and try another knock monitoring setup to troubleshoot the problem.

 

27mm OBD-I

Edit:
I believe an OBD-II knock sensor will use a different sized socket in order to remove.

 

Thanks for the quick reply. In that case, my 1-1/16" socket should fit as it equals to 27mm. Let me get back under the car and try again.

 

No problem. The 1-1/16 socket should fit, as I remember running to the hardware store with the knock sensor in my hand and it worked.

I get code 23 whenever I am cruising above 3,000 RPM. When I swapped my motor out, I broke the knock sensor, however, the plug was still intact to the harness. Replaced the knock sensor with a used one and still have code 23.

 

hmm... still no go. The 1-1/16" socket seems too small. The Prelude is 93 with a H22a that has a 95 stamp on the block. Is it possible that I have an "in-between-year" motor that "might" use an obd2 sensor?

Btw, I didn't get any CEL when it detects knocks. It could be an overly sensitive knock board on the P72 or mis-matched ECU and motor regarding knock frequency range.

 

Well, if you have an OBD-II sensor, the socket should definitely fit over it, as you need a 24mm socket to remove an OBD-II knock sensor. That is bizarre, I know for a fact, that 1-1/16" socket fits over an OBD-I knock sensor; I tried it myself. Are you certain it won't fit? It's a tight fit underneath the intake manifold while you're laying under the car, but it should fit like a glove.

 

Just got a 27mm socket from the store and it fits perfectly! Not sure why the 1-1/16" oil sensor socket didn't fit... Thanks again for the help!

 

All in a days work. Weird how the 1-1/16" socket didn't work...
Lesson learned - always use metric sockets on a foreign car.