# Knock sensor problem **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [September 23, 2009, 8:42pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964 "2009-09-23T20:42:15Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Since\_1983](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/since_1983/32/5362_2.png) [@Since\_1983](https://forums.speedlife.net/u/Since_1983)\ **Post date:** [September 23, 2009, 8:42pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/1 "2009-09-23T20:42:15Z")
hey all, I just swapped a gsr motor into my del sol, The motor is a 12:1 compression motor with a light tune and its tuned to run on 93 octane, I drove the donor car to my shop to do so with zero issues, I swapped everything into my car and had 87 octane in the tank (about 1/4 tank) I threw in some fuel additive and drove it nicely to waste the existing fuel before refilling with 93 octane. I have now replaced the 87 octane with 93 octane and I am still getting this code, if I turn the car off then turn it back on it goes away, and if I drive the car without engaging vtec I get no code, the instant vtec engages it throws the code, as I said the donor car dd not throw this code, and I checked that cel too, it wasn’t blown or anything. any ideas? ---
**Author:** ![JDMSIR](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jdmsir/32/7376_2.png) [@JDMSIR](https://forums.speedlife.net/u/JDMSIR)\ **Post date:** [September 23, 2009, 9:03pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/2 "2009-09-23T21:03:11Z")
Did you unhook the battery or pull the fuse to clear the ecu? Try that and see if it works. ---
**Author:** ![Toda\_Party](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/toda_party/32/7354_2.png) [@Toda\_Party](https://forums.speedlife.net/u/Toda_Party)\ **Post date:** [September 23, 2009, 10:40pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/3 "2009-09-23T22:40:25Z")
OEM knock sensors can’t differentiate between knock and other noise at vtec RPM anyway. do you actually hear any pinging at all? u can try filling up w/ delta 100 (half a tank should be fine) and see if it persists, but yea, clear the code first before anything ---
**Author:** ![Since\_1983](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/since_1983/32/5362_2.png) [@Since\_1983](https://forums.speedlife.net/u/Since_1983)\ **Post date:** [September 24, 2009, 12:14am UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/4 "2009-09-24T00:14:43Z")
cool, I’ll give both of those a shot. I figure it can’t be anything too terrible because this all worked 2 weeks ago. I am just trying to get this to a track and see what it runs before the seasons over ---
**Author:** ![JDMSIR](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jdmsir/32/7376_2.png) [@JDMSIR](https://forums.speedlife.net/u/JDMSIR)\ **Post date:** [September 24, 2009, 12:21am UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/5 "2009-09-24T00:21:23Z")
Not sure if you removed the wire harness when you did the swap but(probably not), make sure its on all the way as well. The rubber outside of the wire harness(gets hard from oil, gas, cleaner and over time), can sometimes be hard to properly seat when putting back on. I have an extra one you can have if you need it, hit me up. Like I said and Toda, clear the codes first. ---
**Author:** ![99\_civic\_si](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/99_civic_si/32/7319_2.png) [@99\_civic\_si](https://forums.speedlife.net/u/99_civic_si)\ **Post date:** [September 24, 2009, 4:37am UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/6 "2009-09-24T04:37:34Z")
well this might sound silly, but is your donor car even wired for the knock sensor and is it plugged in? And if it is, double check the wiring for it near the ecu it should be pin D-3. Make sure it’s there and making a good connection. Also, as toda stated, the knock sensor from honda is kinda useless (I heard v-dub knock sensors work well). I’m assuming with a 12:1 motor with a “light tune” it’s a chipped ecu. Just disable the knock sensor and call it a day. Hell, take it out of the block and sell it on H-T to someone who needs one for an OBD-II car and make some loot. The resale on them is really high. ---
**Author:** ![Muckman](https://avatars.discourse-cdn.com/v4/letter/m/7ab992/32.png) [@Muckman](https://forums.speedlife.net/u/Muckman)\ **Post date:** [September 24, 2009, 6:27am UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/7 "2009-09-24T06:27:19Z")
you swapped the engine harness and ecu too? ---
**Author:** ![Since\_1983](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/since_1983/32/5362_2.png) [@Since\_1983](https://forums.speedlife.net/u/Since_1983)\ **Post date:** [September 24, 2009, 1:32pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/8 "2009-09-24T13:32:28Z")
> [@Muckman](#): > > you swapped the engine harness and ecu too? yeah i swapped the harness and ECU, the car is tuned on an apexi vtec controller, so that all had to be soldered in to the harness as well. The ECU is a chipped p72 ---
**Author:** ![Saxon](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@Saxon](https://forums.speedlife.net/u/Saxon)\ **Post date:** [September 24, 2009, 7:11pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/9 "2009-09-24T19:11:46Z")
id be willing to bet you dont have the knock sensor wired into the chassis, the engine harness might have it but only the del sol vtecs have the knock wiring stock run a shielded wire from the knock sensor to d3, or just get the car tuned and have them disable the knock sensor as they are useless in B series motors ---
**Author:** ![Since\_1983](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/since_1983/32/5362_2.png) [@Since\_1983](https://forums.speedlife.net/u/Since_1983)\ **Post date:** [September 24, 2009, 8:34pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/10 "2009-09-24T20:34:52Z")
> [@alpha earl](#): > > id be willing to bet you dont have the knock sensor wired into the chassis, the engine harness might have it but only the del sol vtecs have the knock wiring stock > > run a shielded wire from the knock sensor to d3, or just get the car tuned and have them disable the knock sensor as they are useless in B series motors wouldn’t the CEL come on immediately then?? At first the CEL would come on when u started driving, never at idl, now it comes on just when vtec engages, ---
**Author:** ![Saxon](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@Saxon](https://forums.speedlife.net/u/Saxon)\ **Post date:** [September 25, 2009, 6:35am UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/11 "2009-09-25T06:35:59Z")
it all depends, i would honestly check for wiring going to d-3 and backtrace it to the knock sensor in reality that sensor isn’t worth a thing and the car should be tuned and the knock sensor disabled especially with your compression i dont think a “base” map is safe at all ---
**Author:** ![Since\_1983](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/since_1983/32/5362_2.png) [@Since\_1983](https://forums.speedlife.net/u/Since_1983)\ **Post date:** [September 25, 2009, 10:01pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/12 "2009-09-25T22:01:53Z")
let me clarify a bit on the tune, it isn’t a basemap chip, the motor was in a friends car, he bought it like this, added a few things then took it to canada and had it dyno’ed ad tuned. it isn’t a super aggressive tune because it was a car he DD’ed I will have some time on my upcoming days off to investigate a bit. I would just like to solve this before the motor gts pulled for a full rebuild in a few months. It doesn’t seem to run an different and for an all motor honda its far from sluggish even with the CEL My main concern is I just don’t want any lingering problems prior to rebuild, I don’t forsee any issues but I still worry about everything. ---
**Author:** ![Toda\_Party](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/toda_party/32/7354_2.png) [@Toda\_Party](https://forums.speedlife.net/u/Toda_Party)\ **Post date:** [September 25, 2009, 10:35pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/13 "2009-09-25T22:35:00Z")
u should still check it out w/ a WB at least. Just cuz it was tuned on one car, doesn’t make it work in another chassis. Different weight (load), fuel pressure, etc can change it up, a lot more than u’d think. just disable the knock sensor, listen for pinging, and check it out w/ a wideband. ---
**Author:** ![Since\_1983](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/since_1983/32/5362_2.png) [@Since\_1983](https://forums.speedlife.net/u/Since_1983)\ **Post date:** [September 26, 2009, 8:08pm UTC](https://forums.speedlife.net/t/knock-sensor-problem/73964/14 "2009-09-26T20:08:55Z")
will do