Well I did a bit of a tune-up today and changing the spark plugs was on the list. It's on a 2007 Tacoma V6 4x4.

Here's a couple of the plugs I pulled out. All plugs looked like the first two pictures, but the driver's side plug closest to the rear of the truck (don't know the # of the cylinder) was a little wet. It was the only one that was wet though.

Plugs likely hadn't been changed EVER. They were the typical Denso on one side and NGK on the other which I've only ever seen done by the factory, and the truck has about 80k miles on it. My guess is those plugs have 80k miles on them as well.

Also it's "interesting" to note that all of the old plugs were eroded away so much that the gap was over .060 on all of them. One was as much as .075 !
No wonder my mileage has been so bad!





Here's the wet one. Again it was Driver's side closest to the steering wheel (rear most plug)

 

Plugs are on the lean side and bottom photo shows some overheating.

 

Those plugs are 50k miles overdue and severely worn. That alone can cause them to look wet or overheated etc...Put new ones in and drive it. Check them again in a thousand miles if you're concerned about it.

 

x2 With them being so far out of spec on gap, That could cause missing and wet plugs till they get hot enough to keep firing.

 

I own a 2003 as well. I have a lot more miles on my beast though. Bought it for 5k with 185000 miles. Knowing I was going to be upgrading the transmission and possibly the motor (which seems to be running like new) I took a chance.

Related to the OP I did a spark plug change on my truck in October since it was running a little rough for my liking. I put in brand new E3 plugs that you dont gap. They are designed around the truck and the truck ran GREAT for the last couple months. Just recently I let the gf drive the truck and she didn't do the oil change I told her to get done. Drove too long and it was just gross. I got back to it to find the spark plugs a little wet (like above) and needing a new set of plugs after the change. I think in this case the plug gap is definitely the reason for the plug condition and would definitely suggest trying another set of plugs. I will get back to what happens when I put another round of the E3's into the engine since they were and are new technology and might be better alround for the vehicle. Btw... when I put the E3's in .... it triggered all 4 of my oxygen sensors due to lower emissions lol.