I've left my S2000 parked for the better part of the past 4 months with the occasional spin around the block and I finally had time to troubleshoot the CEL that came up. It turned out to be CEL 23 / 60.

23 is for Knock Sensor Circuit Malfunction
60 is supposedly Air Pump

I found a couple of threads indicating that it's possible for the air pump to cause the knock sensor CEL but I'm not sure if that's feasible. So before buying any replacement parts, I just wanted to know if there was a surefire way to deduce what's malfunctioning.

-When I turn the car on, the air pump doesn't make the high-pitched whirring noise (indicating failure/malfunction)
-The CEL 23 for the knock sensor stays on even after multiple resets (reset a few times to make sure it was a solid code)
-Car otherwise drives fine and there's no audible knock.

TIA s2ki

 

BUMP. Anyone ever encounter this? Found a new airpump to try in the shed

 

got a new knock sensor, anyone install the knock sensor from the top before on an AP1/AP2V1 ?

 

Got under the car and took a look. Knock sensor broke off despite me not working on this car for the past 4+ months lol