CEL 23 knock sensor issue - Honda Prelude Forum

Standan · 01-23-2010, 06:09 PM

I have a 93 prelude S with H22 swap...for the past three months i have been fighting this CEL 23 knock sensor issue. Ive searched in forums for possible fixes but have come up empty handed and all the forums that did mention something about it kinda dogged around the issue. So far I put a new sensor in...made sure several times that the wire is ok and in the right spot at the harness for the pcm. Lately i put a new exhaust in my car and patched up a bunch of leaks...CEL went away for a bit until today...it showed up the same way it always has. I need someone to help or tell me how they've fixed this problem very much appreciate input

minilogoguy18 · 01-23-2010, 10:26 PM

You must have a loose connection somewhere because code 23 is pretty much saying the ECU cannot find a working knock sensor.

Standan · 02-11-2010, 04:19 PM

Ive checked....even had my college teacher look at it...knock sensor produced voltage...its only a one wire system...im thinking its exhaust related...i put my car on in the air again after i tried to fix a hole at the flex pipe...the same hole came through again...im going to try a permanent fix on it soon and we'll see if my light goes away

minilogoguy18 · 02-12-2010, 09:42 AM

All code 23 is the ecu cannot detect a working knock sensor, I've had this code before. Get a known working knock sensor as well as another ecu (from a friend maybe?) and replace them to see what's causing it.

Standan · 03-20-2010, 08:24 PM

ECU is the only other thing it could be...i put a new knock sensor in light was still coming on...im the only prelude owner in the region so its hard to find someone who has an ecu...closest one is calgary and thats 2 hours it might be worth the trip if my exhaust issue doesnt fix it