ECU errors, plz help (Misfire and knock sensor)

I checked my ecu this morning and recorded two errors on my 95 SE...

0304 - Knock Sensor
0605 - Misfire in cylinder 4

I have to definately address the misfire. To my knowledge, the most common source of a misfire is a bad injector or a spark plug. All six spark plugs have almost 20k miles on them, which leads me to believe that they are still good. But the previous owner of the car replaced a couple injectors as they went bad. Which is stupid, cause he should have just swapped them all, to avoid a paying 300+ dollars in service every time to take the manifold and the rest of the intake system off. I will probably do the service myself if I can figure out what the cause is. Any ideas or heads up?

As for the knock sensor. I use 93 octane, so is it worth replacing? I hope I'm not running a conservative fuel map or anything, that would suck. The lil' bastard is lodged way back under the intake. So myabe il do that if I take off the intake. Is cylinder 4 in the front or back bank?

Well, no matter what im ripping apart the max to figure this out. Just hoping if you guys have been through this before and can give me advice.

oh yeah, if anybody knows where to get cheap nissan parts, i.e. injector, knock sensor, plz tell me where.

Just dropped 400 on new yokohama tires, and need to save every penny.

Thanks

Don't worry about your knock sensor. In my experience, it is a ghost reading. Once your misfire goes away, the knock sensor code will disapear as well.

Twice I have gotten misfire codes and in both cases it was the coil pack. I just took mine to a mechanic, but there are ways to diagnose if a coilpack is bad. If your interested in finding out for yourself, let me know and I will scan the manual page.

BTW, if your not sure what the coilpack is, it is the part that sits on top of the sparkplug.

thanks lordrashmi! never really thought of coils, but if u said they cause problems i better check them anyways.

those manual pages would be helpful too if you can send them to me

thanks!

I am at work now, but will try to scan and post tonight.

Here is the Manual page. Start with the green dot. It is a pretty large image, I just wanted to get a clear picture.

http://lordrashmi.com/pics/coilpack.jpg

I believe cylinder #4 is the center, front.

Hope this helps.

Wow, thanks a lot. This will definately help.

So if I have the same knock sensor code and a misfire in cylinder five it's probably the coil then right?

Most likely. From what I have seen those coilpacks fail frequently.

Most likely. From what I have seen those coilpacks fail frequently.


hmm...how frequent?

Swap the suspected coil with its neighbor, reset the ECU, then wait for trouble code. If misfire occurs in the same cylinder the coil is good. Hence the prob is the plug or injector. Then do the same thing with the plug. If no change of the code, it’s an injector.

Thanks guys, it wa steh coil in cylinder five. It's running like a champ now.

hello but my car has the SES light on again. i took it to dealer on 12/30/03;after 2.5 weeks the light came on again. this time, they told me my warranty is over, and they couldn't do anything unless i pay them $120-$200. when i got my car back, i found that they turned the SES light off by resetting the ecu instead of actually fixing the problem. now i'm like wtf and was wondering if anybody would know how i can still read the error codes that was there before. in other words, is there a way how i can resurface the SES light that was there before? thanks