2003 Accord, 4cyl, EX 4dr.

Been dealing with this CEL for a while. Replaced knock sensor, CEL went away for a week or so then it came back.
Took it to a shop, they spent time on diagnosis, replaced IAC, went over the wire going from knock sensor to ECM, on and on.

The CEL comes and goes as it pleases. Doesn't matter if it's hot or cold since it both comes or turns off during 100 degree summer or snowing winter.
When CEL is on, car idle drops to 500rpms at stoplight while in gear with foot on brake, especially if heater/AC is on. It's stalled a few times as well.
When CEL turns off, car drives just fine and idles with no problem at stoplights even with heater/AC on.

This is getting to be the worst gremlin ever. Anyone have a guess or ever dealt with similar?
Thank you.

 

What specific code are you getting on your accord?

 

Knock sensor. P0325.

 

The setup is pretty simple as the knock sensor is a 1-wire sensor that comes directly from the PCM. The issue can only be the sensor, wiring/connectors, or the PCM. Unplug the sensor and PCM connector 1 and see if the wire has continuity to ground at the knock sensor connector and also a pin A1 to ground (It shouldn't). With the PCM unplugged, jump the connector at the knock sensor to ground and check if pin A1 on the PCM harness has continuity to ground.

While you are at the knock sensor connector, check there is no corrosion on the connector and my spray it with electrical contact cleaner. Also check that the connector isn't open too much where it doesn't fit on the pin of the knock sensor securely?

 

Brilliant. That's exactly the type of thing I was suspecting. The connector looks like a bit grimy and slightly rusty. Water getting into that area seems to line up with it acting up more during rainy season.
I cleaned it all up and coated it with silicone gel stuff to keep moisture out so fingers crossed that it stays off this time for good.

Thank you very much for the run down diagnosis. You are dialed in and I appreciate it.