2k max Engine Surging during warm up

[jsta22]

Ok... soo in my earlier posts, I wrote that I replaced my MAf and had the ECU updated/reprogrammed from the dealer with Really Positive results..
Well, now that its been a couple weeks, I have had an issue where a good deal of power was lost again, and now back, and now that its cold, The engine seems to almost bounce back and forth between 650rpm and 450 rpm, sometimes worse, like its gonna stall, BUT only when cold.. Once warmed up, Runs fine!
ANy ideas this time??

[adidas2go]

Vacuum leak? Move some hoses around when you first start it up and see if when you move somethin the car reacts.

[NutriaforBreakfast]

guessing-see if egr valve is sticking

[jsta22]

Im pretty much done with this car... Im tired of getting work done to it, it feels great, then mere weeks later, back to square one, and those laggy dead spots in the powerband, Like the computer figures out I fixed something, and says, enh enh enh! Caught you, Now I run like s*** again!