FICM fixed...cel back on

[SpeedyLube202]

I had my FICM rebuilt about two weeks ago at a reputable shop but here is the problem, the CEL is back on. When I picked my truck up they said they looked at the EGR Valve and it had a little moisture in it. They said it could be the egr cooler or head gaskets. They quoted me $6800 for everything. Ill sell the truck before I spend that kinda money on a truck I just paid off. I guess my question is why would the CEL come on two weeks after I just had it in the shop? It seems to run fine. I know its hard without codes but maybe someone had the same thing happen to them. Any help is appreciated.

Thanks.