OK guys, thanks to all of the great info on here I figured out how to get the codes out of my ECU. It seems to be telling me two things. I have the two mode ECU in my 94 Maxima with DOHC, and the lights blink two different codes. First 34, Knock sensor. Now I get 51, and It does not show up on the diagnostic sheets. Any Ideas?? By the way further testing does show a faulty knock sensor, btu the 51 is killing me.

Thanks in advance for any help!!

 

what is wrong with your knok sensor if it is not faulty, maybe it is detecting to harsh of a knok to correct, is your idle smooth or does it bogg down and up?

 

I get very high resisitance (over 20Meg OHM)on the knock sensor. When I disconnect the sensor the car ran better for a while, unil it began missing, and the engine light went on.

 

Code 51 is for the injector Circuits.

The resistence reading you are getting on the knock sensor seems High. YOu may want to try searching the forum for disabling your knock sensor.

 

do you have a california model!!?? wow!!! that a rarity!!

code 51 is for open looped fuel injector cicuit-

but remember the first code usually causes the second. replace the knock reset the ecu and see where you are at...good luck man

-Tick

 

Do you guys have a good way of finding which injector is bad? I was hoping to avoid pulling the intake manifold off unless I have to!

 

First, do you have a drivability issues? What kind of issues are there? If you feel your car is driving normally, try clearing the codes. Drive it around for a while and see if the codes come back.

Otherwise, testing your injector circuits is easy, if you have a volt/ohm meter and or a logic probe. I will go more into that after you next response.

 

When I clear the codes the light goes off, after a few seconds the light goes back on. The engine is missing on one cylinder,and the code is 51. Thanks a lot for any help you can offer!

 

First you have to Identify which cylinder is missing. To do this, pull each coil connection, one at a time. Which ever cylinder does not cause a drop in RPMs is you dead one. If it happens to be one of the forward bank of cylinders, you in luck. You can do your tests directly on the injector connector. Otherwise there is a square connector left side of you intake plenum. I do not have my reference material in front of me, but I can give you wiring color codes later today.

The way your system is set up. Your injectors are a 2 wire system. Power is applied to one wire all the time and each injector runs over the same power circuit. The ground lead is connected directly to and is controlled by your ECU. With the car not running, and leave the injector connected. use a multi meter or test light to make sure you have power on both wires of that injector. If you have power on one and not the other, You have a bad coil in the injector and it needs to be replaced. If you don't have power on any wire, you may have a wiring issue. But lets start with this for now.