[sepulchral]

(This faq is for an sr20det, sr20de, ka24de, ka24e?)

If you receive ECU Error code 34, it means one of two things:

a) Bad Knock Sensor
b) Bad connection to knock sensor

Like many things, Knock Sensors can just "Go Bad". First, look for the grey conector between the 3rd and 4th intake runners, there may be two, the bigger one is the o2 sensor, the smaller one is the knock sensor. Unplug the knock sensor connector and check the wiring, likewise, follow the wiring down to under the intake manifold and feel that the wiring hasn't fallen out. Either way you're going to have to remove the knock sensor to thoroughly check. My knock sensor on my sr20det was held on by one 12mm bolt, to remove it i just reached down under the intake manifold and unbolted it, it was agonizing but it worked and i replaced the whole thing in 15 minutes. Other people would normally go from under the car and remove the starter to get to it, or remove the intake manifold. This is not compeletely necessary, but smaller hands do help. When you get the old knock sensor off look for these things:

a) Discoloration of the copper side (means its toast)
b) Frayed wires
c) any cracks in the knock sensor
d) Plug is damaged
e) not receiving enough electricity

If you see wiring problems then i suggest you fix them, plug the knock sensor back in, bolt it up, reset ECU, drive the car, and see if the error comes up again. Otherwise just replace the little demon. If you have an sr20det then go to Nissan or Napa and get the knock sensor off a 1991 Nissan Sentra SER (Sr20de), If you have a CA18det then get it off a Pulsar, KA's should be selft explanatory because they are american made. Knock sensors are not cheap, mine was $118.00 it sucks, but live with it.

Once you have the new knock sensor, replace the old one, double check wiring, bolt it back up, and reset ECU, drive car around, check ecu, if its not fixed then you have wiring issues most likely, that i can't help you with but there are ways to check the electrical charge.

Good Luck