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View Full Version : can a resistor replace a knock sensor


theianmcdougall
09-22-2008, 07:22 PM
redtop sr20det swapped s13

my ecu is still throwing a 34 (knock sensor)
and thought instead of trying to spends hours taking off my intake manifold and spending 100+ on a new knock sensor i would just use a resistor
so i went to radio shack and the highest ohm there was 470
and cut the knock wires and ran the resistor
it almost seemed like it helped but i could be retarded
but the engine still isnt working good
its still running very rich, poor idling and its missing and bucking after 3k when i get on it

could it be the timing or somthing
i've ran out of idea's
whats the deal

Massimo Power
09-22-2008, 07:26 PM
Check all the wiring for the harness.. exposed wires can cause many problems and the ECu wont know exactly what it is...

and yes check timing as well...

MELLO*SOS
09-22-2008, 07:28 PM
1) yes it can replace. I used a 1Megohm but I think a 470k will work also.

2) Usually a code 34 means one of two things: Either the sensor itself is bad or the wire going to the sensor is shorted out (very common!). If you have a DMM you could track down the short in the sensor wire and save yourself $100 or w/e it cost for a new sensor. Wouldn't you be pissed to replace the sensor only to still see code 34 from a shorted wire hehe

3) Make sure when you installed the resistor you put it on the right wire (duh) and that the other side of the resistor is connected to a GOOD GROUND (very important). If the other side isn't a good ground, it's the same as a short/bad sensor = code 34. Use your DMM to check it out!

4) You will be able to tell if it's working or not, because after you do all this and clear codes the code 34 will go away for good. You'll either have a code 55, or some other shit to battle, but not a 34... If it comes right back then you didn't wire it up right.

Search my threads and/or for 'code 34' and you'll find more info on this code and the resistor thing. I don't think it's that great of an idea on a turbo car due to the risk involved with knock on poor gas, high temperatures, etc. But it's your ride!

theianmcdougall
09-22-2008, 07:37 PM
yea true
whats a dmm?

yea im not really worried, its kinda teporary i just dont wanna take that manifold off and pay that much money for now

SexPanda
09-22-2008, 07:40 PM
yea true
whats a dmm?



I think he meant DSM. What you need to do is go get a DSM, and blow the 4g63. It'll make you feel better.

lol. Nah, I've heard alot about shorted wires to knock sensors lately. Just take your time, go through, and look for any obvious cuts, splits, etc.

And blow up a DSM

aNskY
09-22-2008, 08:07 PM
Digital MultiMeter

if you are doing any work on any automobile wiring i would HOPE you have one.

Bigsyke
09-22-2008, 08:13 PM
Um wrong;

Code 34 can and will be set off for plenty more reasons than the KS itself.

Wiring short;
KS unit cracked or defective;
Inproper octane
Drive/valve train rattle or slight vibraitions.
Hell even a stuck caliper could cause some ping to set off code 34.
Coolant Temp sensor.
In proper timing
Anything that could affect A/F adn engine operation such as;
EGR system or Evap/Carbon canister.

Code 34 is a bitch and chances are unlikely its the KS itself, unlses you have overheated and cracked the sensor, but then you have much bigger issues.

projectRDM
09-22-2008, 08:21 PM
Um wrong;

Code 34 can and will be set off for plenty more reasons than the KS itself.

Wiring short;
KS unit cracked or defective;
Improper octane
Drive/valve train rattle or slight vibrations.
Hell even a stuck caliper could cause some ping to set off code 34.
Coolant Temp sensor.
Improper timing
Anything that could affect A/F and engine operation such as;
EGR system or EVAP/Carbon canister.

Code 34 is a bitch and chances are unlikely its the KS itself, unlses you have overheated and cracked the sensor, but then you have much bigger issues.

Bingo. The man is learning well on here. +1 to you if I could.

fliprayzin240sx
09-22-2008, 08:48 PM
Why dont you try to fix it properly so you wont make shit worst in the long run. Besides, cant you get to the knock sensor from under the car. I know in my SR, I've gotten to it from underneat after I forgot to put it back on the block.

Bigsyke
09-22-2008, 09:38 PM
Bingo. The man is learning well on here. +1 to you if I could.

its all you sir!