i had my car tuned after a bc 272 cam install and if the car cools down for 10 15 mins it takes 3 cranks on the money 3 cranks to start up again. why is that?

another issue i'm having is check engine light is on and the code is egr. i replaced the solenoid and still the same thing. it goes away lately. it used to be on all the time but now it goes away more frequently but as long as i spend a half hour of highway driving it comes back on. i just don't get it . it's killing me.