!@$%^& knock sensor!!! - Honda Prelude Forum

popwar · 11-24-2010, 08:00 PM

i've had the code ever since i got my lude ( 95 se h23a1 , p14 ecu ) . when i first got it before doing a tune up the cel 23 wld come on then go off , but recently i just fixed the timing that was off 2 teeth and it has more power , running like it should , but cel 23 still there . i've tried to ground it , made sure it was tight , could it be the o2 sensor throwing the code? made sure it wasnt the ignition coil . it doesnt come on unless im going up a hill or go past 55mph i dont get it. i know theres other threads on here about the issue but i dont see solutions that work for me . please any suggestions , its using too much gas with it on , though i turn the key off and back on and it goes away temporarily til it comes on again .

minilogoguy18 · 11-25-2010, 08:55 AM

Have you actually checked the sensor itself? They do go bad ya know, it's very common.

Do the ECU reset procedure by pulling the clock radio fuse or disconnecting the negative battery cable. Start the engine and rev it to 4k for a few minutes and if the CEL comes on check the sensor and the wiring going to it. More than likely the sensor is bad and it is obvious when they do because the plastic portion will jiggle and the sensor will more than likely come apart when you touch it. It's located in the back top center of the block directly underneath the intake manifold. You'll need a 27mm deep socket and a very short ratchet to remove it. Good luck, they cost about $160 new and I wouldn't buy a used one.

popwar · 11-25-2010, 11:18 AM

its a new sensor . Tried what u said , still there

minilogoguy18 · 11-25-2010, 04:41 PM

Just curious even though it may or may not make a difference, what octane fuel are you running and what brand?

Did you actually test continuity between wire D3 and body ground on the main harness and also from the connector itself? Could be a short somewhere. Also, is this a new sensor from the dealer for that car?

If you know anyone as well with a Prelude and the same ECU as you, you might have to try a known good ECU to see if there is a problem at the ECU itself. Other than that I'm out of ideas and I pretty much stated everything the factory manual suggests.

popwar · 11-25-2010, 05:46 PM

its a duralast sensor . i got it for 40 dollars from a friend . i use only premium . w/e premium is cheaper . usually BP or speedway . ill try the ecu switch

minilogoguy18 · 11-25-2010, 06:12 PM

That aftermarket sensor is more than likely the problem, aftermarket stuff for the most part is junk compared to genuine parts. If the ECU and wiring checks good then your cheapo sensor is to blame, go to the dealer and get a genuine Honda sensor.

popwar · 11-25-2010, 06:39 PM

the old sensor looked the same as the 1 thats on it now but found out the plastic part was broke off though when i first looked at it , the stock 1 i assume , the CEL code 23 came on then back off while driving . just 160 dollars ... thanks for your suggestions