Are all the spark plugs you are using the same brand/type?

normally if the ignition coils got mixed up it throws a multiple misfire code i think?

 

Don't think it would cause a problem, other than the danger of igniting any fuel vapor around.
However, it isn't really a good diagnostic process for the coil pack. A faulty coil pack may still produce a spark in open air, but not produce a strong enough spark to ignite the fuel mixture under compression.

If you get no spark, then either the Coil pack has failed, or the wiring to the coil pack is faulty.

 

My concern was more electrical damage. I don't want to recommend someone do something that is potentially harmful.

 

What I see in this thread is you still haven't touched the 1, 3, and 5 plugs/COPs. Your problem might exist on that bank so look over there.

I don't know what you mean by "impossible" a lot of us have replaced plugs on that side with no issues. You just have to move a couple of wire harnesses to get to the COPs and it will take some time, but I wouldn't even put it in the "difficult" category.

 

But how can they throw a P0304 error? I thought it was specific to cylinder 4

However, I will take your advice and make another attempt to get those wire harnesses out of the way. I unscrewed everything and those things just won't budge!

 

No, I only used the NGK platinum ones for # 4 and 6 since they had a lot of oil in them. And used the regular NGK plug for # 2 and didnt even bother changing 1,3,5 since I couldn't get the wire harnesses out of the way.

But I have been advised to change all of them, so will give it a shot this weekend.

Also a thing to note... the passenger side valve cover is bone dry while the drive side has oil ALL OVER it. I knew it was leaking (since I found oil in the plugs) but this thing is wet and black.

 

Will try to switch 4 and 6 this weekend. I am not too savvy to check for spark the way you showed but I noticed in other thread that people removed the COP one at a time and checked for difference in RPMs. If nothing happens that means that COP is most likely shot.

However, what I dont understand is, when I changed the driver side plugs I had to remove the big air pipe and I am not sure if I can turn the car on with that thing removed, can I? So do I really have to literally unplug one COP, put everything else back together and start the engine???

 

P304 is cylinder 4.

A quick read of the FSM shows that the numbering is 2,4,6 on the driver's side, and 1,3,5 on the passenger side.

That's why i asked if you were resetting the code and seeing the P0304 come back each time. I was thinking that if it was the other bank, you would see a P0301, P0303 or P0305 pop up.

But if the P0304 comes back each time, then i would be sure it's cylinder #4

 

I haven't erased the code but since I am taking the negative terminal off the CEL disappears after each change I make. Then after a few minutes reappears and only shows P0304.

 

Yeah, that's a HUGE Pita. Like i said, i usually do this on older engines where there is not much in the way.

Don't do my method just yet...

 

How long do you unhook for? 20 mins or so? or a quick unhook?

You have a scanner? Are you able to manually erase codes through the scanner.

Just want to confirm it's not a phantom, and is truely being cleared out.

 

Yes I had a reader. I will try to manually erase the code but the problem with the misfire is that I can clear the code all I want, the misfire can still be felt when I turn the car on.

I feel the engine shake, a low farting noise from the exhaust and the car struggles to accelerate

 

Another update: So my local mechanic (who couldn't fix or determine the problem) took the car to another guy who ran some sort of diagnostic test and said that the piston might be damaged?

Does this sound like a plausible problem? If so, what kind of damage am I looking at? I will be taking the car to a couple more guys before I decide to get a mechanic to actually attempt to fix it.

Til then I will do everything you guys have proposed so far, one more time.

 

You're right about the technical definition of the code, but if it were me I'd check all cylinders just to rule 1-3-5 out.

 

I'm wondering if he did a compression check?

If you go on YouTube and search for compression testing, you'll see how it's done. Basically if you check all 6 cylinders, the values should all be within a small percentage of each other. If you find one cylinder way off, then you have an issue.

Could be either rings, or a bad head gasket. Usually a shot of oil in the cylinder and a quick repeat of the test can tell if it's rings if the oil causes the numbers to rise. Then it would suggest head gasket.