96 S10 Blazer P0440 Code

Replaced my engine about 3 months ago and just today came up with this code. It appears to be evap emmisions. Is this a closed system? Is there one hose more then another that rots out? Or is there something else I should be looking for? Ive checked the gas cap. I didnt replace it though. Just checked to make sure it was tight. No drivability concerns.

if it took 3 months for the break in period for the engine then damn. but the engine may now be coded for the computer. if the old computer was coded for a california emissions and the new engine is a federal emissions then theres your problem. if not then trace your emissions system for problems. since its a code then its a sensor. is no faulty sensors, then look into what the code means.

There is a leak in the evap system and there is one to find it,a smoke machine which work great finding the leaks.Many companies make them using baby oil.Snap On's has to use their oil only which is not cheap.Greyish smoke should come out where the evap leak is