03 6.0 starts rough

[ccocita]

my 6.0 has 35000 on it no tuner but has egr del and cat back.about a month ago it started very rough then smoothed out,it only does this on first start in the am ,i am in SO CAL so it is probably at least 45 degrees out,then after it smooths out 60 sec later i get a brief acceleration ,odd problem but it is consistent.Just wondering if anyone has heard this before and had any suggestions thank you SAM.