00 GT Idle issues

Fellas,

Started the car this morning and it would not idle. Would run fine if I had my foot on the accelerator but if I let off would fall on it's face. Took the tune out and put back to stock and still did it. No codes shown on the SCT either. I tried it a few times and then all of the sudden it was fine. I'm assuming some sort of idle sensor is on its way out but looking for suggestions.

I should add that it's fallen on it's face before when coming to a stop at a light but hasn't done it again until today.

MASS AIR is clean
intakes clean
Tunes back in and it's running fine again.

Confirm battery connections + ground cable at the engine itself are spotlessly clean and tight. Did you clean the MAF since it started the problem or before?

Battery cables are spotless and clean. It was a month or so ago when I cleaned the MAF. It's done it once at a light and never again until today.

Where's the ground connection on motor?

By the way I'm ready when you are to install the frame connectors

Ground connection is on the side of the block (4v is on drivers side, can't recall if 2v is the same or not). Be sure to clean the body ground on the rad support as well. With oil style air filters, not uncommon for a tiny amount to hit the MAF n cause all kinds of driveability issues. The odd time, it's just a shiat happens kinda deal n cleans itself up.
You'll like the connectors for sure.

The IAC on these are fairly prone to failure as well. I keep a spare Motorcraft unit in my cars glove box because.

I'm wondering about the IAC Laffs. It's original and being 15 yrs old I wouldn't be surprised. Only has 71k but you never know.