Code P0300 water Intrusion on a spark plug, causing sputtering at idle

Thank you HMac300.

Thank you for looking very carefully at the 3 photos of the four spark plugs.

You say, "It [is] probably fouling from driving only a couple of miles a day."

1. Can you please tell me what kind of fouling you see?

Is it oil and/or gas and/or water fouling, please?

2. How many spark plugs are affected, in your opinion?

3. Would replacing the affected (or maybe even all) the spark plugs and wires---at a minimum---be a reasonable next step, followed by driving it more to get the excess fuel out?

Thanks again, HMac300!

Thank you all for your responses, even though they are different, so I don't know what to do or think. Still yours are not the only opinions I have sought in my exhaustive quest to figure out what my mechanic did.

Cadieman, the mechanic did not mention, nor say on the work order, that he removed the oil cap. I will try to get someone to do that.

Everyone I've shown the plugs to, whether master mechanics or parts salesperson, whether in person or in an online forum, everyone has an entirely different opinion of what the issue is and how to solve it. That is not a criticism. It is just a fact. And it's driving me nuts.

Every time I ask this question, I get new answers. And then I do more and more research and get even more confounding information. I'm at my wits' end.

The most consistent response, however, is that 2 of the 4 plugs look like they have gas/oil fouling, but not how it happened (like HMac300 said). Most opinions are that the other 2 plugs look fine. They suggested that a good start would be to replace all the plugs and wires, followed by a tune up if necessary.

But HMac300, I gotta tell you, man, your reply makes absolutely the most sense to me. I DO only drive a few miles a week, and so the car's temp doesn't go high enough to reach that important temperature necessary to burn these residues off, right? And, since I've not gotten to that point, nearly for years, these plugs show up as they do and need to be replaced. My money is on you HMac. But there is more to this.

And that is not what my mechanic said and not what he did.

Instead, after he determined the plugs had water intrusion, he "pressure tested cooling system" as the next step and this showed that "cylinders 1, 2 and 3 are leaking coolant."

So, my next questions are:

1. If those 3 cylinders were so damaged, wouldn't that show up as codes P0301, P0302 and P0303 on the scanner? You know, as opposed to the original reading of P0300?

2. How does coolant get inside the cylinders?

3. Wouldn't there be several tell-tale signs of this "coolant in the cylinders issue?" Like white smoke or overheating, which was not the case?

There is more to this, of course, but I shall wait for your learned and wise replies, and then I'll drop the water (intrusion) balloon.

Thanks!

Wordlover