These motors do have issues with the EGR valve gumming up, removal is easy, and would eliminate it if it doesn't fix it
You could also check the MAF and all hoses for damage
As there are no codes, it is a bit difficult to diagnose and it would be a process of elimination, if you can do a few simple things it may reduce your mechanics bill
It could be a number of things, but lack of smoke and easy starting would have me heading away from injectors
There is also a filter on the PCV which can get blocked

