after i turn my car off and walk to the back i sometimes notice what i think is a little bit of heat and smoke coming from the exhaust pipe. it doesnt smell and its not blueish black. can it just be from driving the car because im jus worried hoping its not burning oil or anything. just need some opininos

forgot ot add its not the stock exhaust
its a hks catback.

 

maybe something got caught on it? like a plastic bag or something.

 

new exhaust? could just be breaking in and burning off some oil or residue or soemthin inside