My check engine light is on and it is flashing code 55. I think this code refers to one of the knock sensors. Does anyone know what to do to fix this? I have also seen it may refer to the ecm or pcu? Anyone have any ideas?

 

Forget to mention I have a 93 ES.

 

There are two knock sensors, one for each cylinder bank. It is located in the cylinder valley, right under the manifold. The code indicates that the computer is not seeing the proper signal from the sensor on bank 1. Has the manifold been removed from the engine recently? If so a pinched wire would be the most likely suspect. I would first remove the harness from the ecm, and ohm it out. Since you have a knock sensor on both banks, you have the other sensor to compare it to. Make sure to ohm across the terminals, and also to ground.
Check all visable wires around the cylinder valley, because the few minutes that you spend looking could possibly avoid pulling the maniflod.

 

Which one is bank one? Is that the one in the front of the car or the back toward the firewall?

 

Bank 1 is the rear bank, next to the firewall. Bank 2 is next to the rad.

 

Basically what happened was I had an injector go out so I pulled the intake plenum and the fuel rail and replaced the bad injector. Once I put it all back together everything ran great and then all of a sudden the car ran like crap and the check engine light came on saying error 55. Is there anything I can check without pulling the intake plenum again? The last time the manifold was off was probably a year ago when the timing belt was changed.

 

First give a good visual inspection. Do you have a wiring diagram? Because the nest step I would recomend is pulling the connector on the ecm and ohming out both Knock sensors (so that you can compare the two). It would be a good idea to go to Radio Shack and picking up a couple pins, some banna plugs, and speaker wire, so that you could build a set of test leads. The idea is to have a set long enough so that you could hook up you ohm meter and then place the meter in a location that you can see while you wiggle the wire harness.
If you don't have a wiring diagram, send me a Pm. I can email one to you. I tried to upload it, but it is a little too large for this forum, (the file is app 700 kb)

 

 

yes i just replaced before the wife busted the engine twice its a piece of cake...but before ur try to replace them check the wireing harness first

 

Another thing I thought might be helpful to mention is that I broke the wire to the red vsv connector which if you are looking from the front of the engine it is on the left on top of the intake plenum. It broke right at the clip. So I am not sure if this could have something to do with this code being thrown or not. I was going to try to resolder the connector. If that has nothing to do with it then I guess I will try unplugging the ecm wiring harness and plugging it back in and see if maybe it just came loose when I was taking everything apart. Also, strangely enough I also noticed I that now the radio is picking up noise from the engine. It seems like the noise increases with the engine rpm so I must have a ground loose somewhere as well or maybe they are all from the same thing. Not sure.

 

Those knock sensor wires are quite fragile over time. Most likely it is a broken wire from when you removed the intake.

 

i agree with him aswell