2010 Honda fit sport engine knocking noise. Only 86k miles
 

Link to the video I recorded of the sound:
https://youtu.be/plIPlo5D6dk
Have been doing a lot of research and can't figure out what this noise is. It can mainly be heard at idle, but it's inconsistent. Started out quite but has gotten pretty loud and annoying. I've seen some stuff about how it could be piston slap, seems like my mpgs might have gotten slightly worse but might just be from my driving cause it's only by 2mpg avg. Oil is perfect and not dash lights at all and seems to run fine. Lmk what you think.

Sounds like your belt tensioner maybe? Or something to do with the belt? Doesn't sound like piston slap to me. At worse it could be the torque converter but I don't think so. Take a look at the tensioner?

Thats kinda what I was thinking, I did some more investigating of the noise and I think it's coming from the ac compressor pulley. But I'll check out the belt tensioner too. Thanks for the reply!