Code 23...knock Sensor...

[Mindless]

Whats up guys. I usually just lurk but I need some help. I got a H22 swapped cb7 from a buddy of mine. Story is he has too much money and has too many toys and got frustrated with the CB and just let it sit. There was nothing majorly wrong with it outside of a grumpy tranny and little stuff (fuses, bulbs, etc). So I cleaned the car up and began fixing everything. So I saw it was throwing a code for egr and knock sensor. Fast forward to last weekend and I finally get around to putting a new knock sensor in (idk why he didn't put one in to begin with....its not like him to half ass shit). So I screwed the ks into the engine, made a pigtail (all soldered and shrink wrapped), and pinned it into D3. Took the car up the road and after about ten minutes cel came back on. Didn't bother checking the codes again until day before yesterday and guess what....still a code 23...wtf? Go to chang tranny fluid last night and decide to test continuity in pigtail wire and it ohm'ed out fine. Made sure the plug was securely attached to knock sensor, reset the ecu, and took it up the road....same thing. No cel for about 10 minutes and then it popped up with code 23 again.

So my question is wtf am I missing or doing wrong here? This is my first h but not my first honda. Car is running a p13 ecu and the knock sensor is brand new (I guess it could be bad but damn...). I just hand tightened the ks in place when I first installed it (didn't have a socket big enought to tighten at the time) but I tried getting it out last night by hand and it wouldn't budge. If it's not tight enough will it vibrate too much and cause a code to be thrown? Car has innovative mounts and vibrates a lot as is and the balance shafts have been eliminated as well. Could any excess engine vibration contribute to the problem?

Any help is greatly appreciated.

[RustyBucket]

Have you checked the resistance of the knock sensor at the terminals of the sensor? Was the engine hot or cold when you did it.

It sounds like it could be a termperature-related issue with the replacement knock sensor or connectors. You said things are fine when you reset the ECU and then the code comes back after some driving.

Check the resistance at the ECU end of the pigtail as well as at the knock sensor when it's cold and again when it's hot (and throwing the code).

I get an occasional CEL on my Q45 for the knock sensor which behaves a lot like what you described. In my case, the CEL goes away when you shut the car off and restart, but it will come back after driving for a bit. I know in my case that the ohm reading on one of the knock sensors is iffy and I would not be surprised if it's a temperature related thing. I suspect the harmionic balancer may be on its way out, but that is only occasionally noticeable at idle, not under driving conditions.

I replaced one of the knock sensors last year and I am kicking myself for not doing both because on the Nissan V8 engines (or at least the VH45DE) the sensors are in the valley between the cylinder banks. The job absolutely SUCKS because you have to take off the intake plenum which involves a bajillion vacuum hoses and then once that's off you have to take off the coolant crossover hose between the banks to get at the sensors.

[Mindless]

Have you checked the resistance of the knock sensor at the terminals of the sensor? Was the engine hot or cold when you did it.

It sounds like it could be a termperature-related issue with the replacement knock sensor or connectors. You said things are fine when you reset the ECU and then the code comes back after some driving.

Check the resistance at the ECU end of the pigtail as well as at the knock sensor when it's cold and again when it's hot (and throwing the code).

Rusty, I'm not sure what you mean by checking the resistance at the terminals at the sensor since this is only a one wire sensor. But the engine was cold when resistance was checked between sensor plug and ecu plug.

[Mindless]

Ok I just remembered something and I have a question:

Would timing effect / cause this? Only reason I say this is because right after I got the car I noticed the dist was advanced so I just bumped it back so it was in the middle and the car had zero power....I couldn't even get up a modest hill on the highway without slowing down from like 60 to 30mph. After that I put it back to its original "advanced" position and the car drives fine. I have never thought it was lacking in power (even though I have never driven an H) and was very impressed with how the H22a moved my 2800lb sled. The car has an aftermarket flywheel and when it was put on the timing marks on the flywheel weren't lined up at all.

[wed3k]

if its advanced then it could be causing the knock sensor to go crazy. id say try and find tdc as best as you can via cam positioning, markt he flywheel and go from there.

make sure you short the SCC connector while checking timing. check your idle speed as that affects timing.