fluctuating idle,when cold and warm.

Hello, This forum is for folks with issues that need guidance, not a place where people can touch and feel your vehicle and diagnose the present concerns. I know that's obvious, but I'm thinking your expectations are such that we can just guess at what's going on with your vehicle. True, with the decades of expertise that many of us combine to have, we can "guess" into a direction, but those same decades of experience also know better than to suggest or theorize without getting some of the important facts that don't send us off on a tangent that will likely cost hundreds of dollars or more and resolve nothing. Evidence of this would be the questionable need to replace the "IAC, TPS, plugs, fuel regulator, EGR". What if you could have kept that money and fixed the actual problem you are having? This is why we suggest a professional diagnosis. All that said: engine performance is at it's most basic elements comprised of appropriate amounts of fuel pressure and delivery, spark, air coming into the engine in the correct places in the correct way at the proper time, and exhaust being allowed to escape also in the correct passages in the correct ways. It also adds to that emissions controls that when malfunctioning can negatively affect those 4 elements. Your concern at least sounds from the outside like something to do with air intake or engine vacucum. But guessing is not helpful. Good luck.

Many possibilities - Recommend professional diagnosis: ▪️https://repairpal.com/repair-shops▪️