2Glides

Hi all, I'm new here, I recently had some issues with my truck and hoping that someone here can help me. Last weekeknd out of hte blue, my truck died about 1 mile from my house. Nor electrcal, seemed like fuel. I had towed to the dealer. they siad it was my fuel pump control module. Nice place to mount that up over the spare tire....... anyway, $500 later the truck runs again. I'm not sure how long it was after that, (1 or 2 days), I got a cel. My friend pu t his reader on it and it said evap system vacuum leak, (very small). About this same time the idle is eratic especially when warmed up and holding the brake in gear. It will drop 100 or so RPMs and then go back. Cold idle the engine shakes at a faster pace. IS there a chance that the dealer inadvertantly disturbed a vacuum line under the truck or should I be looking elswhere. I don't want to just start changing parts until I find it. I understand that places like Firestone can put smoke in the system to ddetect leaks. Is this what I shoud do first seeing the code? Also I am getting a gas smell mostly after start up on a cold engine. I don't smell it while driving. I had the fuel rail and that checked and found no leaks. I could use some help and would appreciate any help that I can get here.
Thank you in advance,
2Glides