Nissan Repair: not really sure if it means something is worng, radiator coolant, nissan pathfinder

Question
Hi....i recently got my license...so i am not so use to knowing whats what about my car...i have a 2001 nissan pathfinder....and i got an oil change there a month ago...ever since then....when i turn the heater on i smell gas...and also it is not alot but i am getting a off white kinda smoke coming from the tail pipe...kinda reminds you of when somone blows out smoke from a cigarette....i dont drive the the car much maybe once or twice a week...but i do start it up every few nights to make sure it doesnt sieize up...also i was wondering could this smoke just be from the weather change...lately we are having really cold weather...please help....i dont have a clue what is goin on....thank you,  

Answer
Sounds like you need to take it for a good long highway ride. Cars with fuel injection do not have chokes but a cold idle solenoid that actual floods the car to make it run when it's engine is not a full operating temperature. Hopefully, what you see from the tailpipe is just from the fuel. Keep an eye on your radiator coolant and engine oil. I am concerned about a possible headgasket issue.