Okay so after donating blood today, I stopped by Auto-zone on my way home to pick up some new windshield wipers since it was starting to rain. When I got in the parking lot, I noticed my truck seemed to have a semi-rough idle. Well, after installing the wipers in the now heavy pouring rain, I got in my truck and started her up. The idle was still rough and my check engine light was now on.

I bought a scangaugeII I mounted in my dash a while ago that read codes and it said it found 3 codes, but they all must have been p0304 because when I cycled through next codes, the listed code stayed the same.


I had to drive home on the highway and when I gave the engine a bit more gas when passing someone in 4th gear, the engine light started flashing. After I passed the other car and went back to 5th, the light stopped flashing, but still stayed on. It didn't flash the rest of the way home, but I was pretty easy on the gas.

I know that p0304 is the code for a misfire on cylinder 4. It is still raining here, so I haven't wanted to go outside to mess with the truck yet, but I'm hoping someone can point me in a direction what would help me correct the problem the fastest when I get a chance to check things out.


I know I should check the plug/wire to cylinder 4 so I'll do that first. I may not have put much di-electirc grease around the plug when I replaced them a couple month ago, so is it possible the plug end just got wet and that could set off the codes?

I have read that a leaking intake manifold gasket could also cause this, or a possible ignition coil problem that can set off misfires. I would think if it was my coil, there would be two misfires though right?

If it turns out not to be my plug/wires, I am not too savy with knowing what the next likely culprit would be.

I'm hoping it's not an exhaust problem that would cause this. I believe I have a small exhaust leak after putting on my headers, and I haven't yet purchased copper gaskets and locking bolts. Does anyone know if a possible exhaust problem could throw this code too? I just remember too, that my scangauge says my truck is stuck in open loop... so maybe that can contribute to the problem?

 

Haha.... mystery solved! Now that it stopped raining and I had a better chance to actually check things out it was pretty obvious.....

With my Bassani Headers, its pretty hard to securely push in the plug wires, especially in the back. I went to pull off the #4 cylinder wire and it wasn't even attached.. the rubber boot was just resting on the tip of the spark plug. I think that probably causes some misfire. The Bassani headers are awesome, but make dealing with the spark plugs a little bit of a hassle. I still am having trouble having the wire 'snap' on the tip of the plug, but with it on there better, I could tell there was no misfiring.

I now need to find that thread that people were talking about where the bought a spark plug socket adapter they used specifically for these headers... without it its a little too hard to get some of the plugs out! Oh well I won't need to change my plugs for quite some time!