Weird rattle noise/cold start choke @low gear

nissan
sentra

#1

my '07 sentra has just under 52K and has had all regular maintenance. for the last 6 months or so it’s made a faint rattle, it sounds like from the rear passenger side. no one can find it. and now in the last 2-3 weeks it has really rough cold starts and almost chokes/stalls at lower gears. once it’s warmed up it runs fine, although the rattle is louder when it idles. i can’t get it to reproduce the stalls for my mechanic, but it’s definitely there!


#2

The rattle could be from inside the muffler. Which side is it on?

For the cold stall have fuel pressure tested when cold.