Make Jim F's code reader but you won't be able to believe what it says until you replace the harness.
Like I said before, the areas that are the most hidden are the areas that rot the most. Under the air cleaner, look inside the hard black housing that runs along the passenger side of the engine, you'll see some more scary wire insulation rot. And that CTS wire? The further inside the sheathing you go, the worse it gets. You probably haven't seen the worst area cause it's too far in.
I was told over 4 years ago on a thread that my harness was bad. I looked, checked and found nothing. I posted that they were all wrong and the wires were good. Three years later I was at a junkyard and saw an M119 car partially disassembled and saw that area inside that housing. It was scary! I went back out into the parking lot and immediately checked mine in that area. It was scary too! Yes, I've milked that rotten harness along now for over 4 years but that doesn't mean you need to. If it's bad, replace it. Even if it's not causing problems now, why wait for it. It won't be pretty when it get's you and it will be at the worst possible time too. I'm on borrowed time with mine. And it does have days where it causes me maddening fits. But at least now I know what's causing it.
It is true we do not replace anything unless we know for sure it needs to be replaced, but in this case, we now know it does so we should.
Even if doesn't cure the issue, it wasn't wasted time or money cause it was something that needed to be done anyway.
Regards, Eric