1997 Subaru Outback hesitation and stalling wet weather?

On three isolated occasion my subaru had begun to hesitate and stall. Each time it has been raining out, but has happened on completely isolated incidences. Took to a mechenic, left overnight and the next day it was fine. He said the error code was related to the MAF, but it looked fine to him. Happened again today, and I replaced the air filter and cleaned the MAF thinking that might be the problem. Did not solve the problem. I m going to try and wait till the weather get dry and try again. Any idea why this might be happening?

When is the last time you replaced the spark plug wires? Stalling and even no start conditions when it’s raining usually means the spark plug wires are weak.

You can count this as a second vote for changing the spark plug wires.
If they are the originals, they are long overdue for changing.
Even if they are not the originals, they are still my prime suspect.

We seem to see a lot of issues with Subaru spark plug wires. Wires don’t last the life of the car. They are a maintenance item. Sounds like it is time for new ones for your car. I strongly recommend you get OEM wires. The cheap ones are… well cheap. Worse yet, are the fancy fat colored jobs that cost a lot more and are every bit as good as the cheap ones.

Thanks for your replies, I have to check on the age of the spark plug wires. The behavior is really strange though, for some reason something tells me it is fuel system related, it will idle fine, then drop down in rps, hesitate, and often rev back up then stall again. would bad wires create this behavior? or would it be a consistent issue?

When plug wires go bad in a humid condition the rpm can be all over the place. Look under the hood in a dark garage when the wires are wet and you will get a light show like no other. Don’t reach in and touch anything though.