Intermittent problem after driving in fog, high humidity

I have had a problem with my car that has happened in at least 4 occourances over a span of a couple months.

It only happens after drivin in fog, high humidty and doenst stop untill "fixed"

This is quite long, and I apologize for that, however I’m so confused the complete detail is necissary to describe what the issue is.

The “problem” is either one of two issues, or both. First, the car will drive fine, and will run fine above idle speeds. When the car is at idle, the rps will shift between 1200 and 400 a few times, then hold steady at where it should be. Sometimes the rpms drop so low it dies (at stop lights, and such however this happens more-so when the car is shifted into park). If the car is driving at cruising speeds, the low rpm speed doesn’t seem to be affected. The second problem is much like the first however while cruising/accelerating it feels as if the motor is just cutting off. It will buck, the rpms will drop, then go back to normal. (this happens sporadically, with no set time intervals between each buck/cut-out) I find myself having to shift into neutral and maintain a slightly higher rpm with the accelerator to keep the car from dying at stop lights.

Sometimes the problem is a combination of the two issues.

The problem doesn’t start to show until the vehicle starts to become warmed up, and the motor temp is near its normal operating temperature (which the normal operating temp when the problem exists is the same as when it doesn’t)

The three times this has happened have all been after a very humid morning, and the CEL always comes on when the problem exists. The first time the code was ran, it came back MAS low voltage, thus I replaced the MAS, and the car ran perfect until the next morning of high humidity. The next time, it started acting up I ran the code it was throwing, advising me to replace the MAP sensor. Thus, after doing so the car ran great until the next morning of high humidity. This time, the car sat for about a week before I had time to get under the hood and look at it. After doing some research I did the spray bottle test in my garage with all the lights off to check for arching, after being unsuccessful in locating any arch I began checking the wiring to and from the map and mas sensors, as well as the plug wires and such for baring or abrasions. After still being unsuccessful I removed the map sensor and physically inspected it for any abnormalities. After all my attempts at locating a problem were unsuccessful I plugged everything back in, started it up and it ran fine for nearly 2 weeks before the next humid morning. Now I’m at the fourth time of this occourance over a span of several months. It started yesterday morning on my commute to work. After getting off work in the evening (with the vehicle sitting much of the day) I tried removing the map sensor and such in a manor similar to following the same steps I did when the issue came up for the third time thinking somehow I reset something. This did not solve the issue. This morning, it was very humid and foggy again and it seemed to have made the problem worse, elevating to not just symptoms of the first issue, but symptoms of both issues.

Keep in mind, the problem begins after a high humid, foggy morning; not during rain, and will continue until the issue is resolved.

Any help is very much appreciated.

Thank you.

First, what engine and model year do you have? what was the exact code number?

1999 3800 II 3.8L v6 - I'll have to grab the codes when I get off work.