Ive been hearing this rattling noise as I let off the gas, normally stops when it get down to 10mph.
Today the check engine light turn on and I don't hear the noise anymore? (Weird)

I've been told that I might have to replace the timing chain.
*btw car still runs but it hesitates when I step on it.
Is someone familiar with this problem? If so, what would I be better of doing?

 

Have you checked for any fault codes since the check engine light is now on?

 

Welcome to the forum. Please add some detail about the vehicle so we know what we are talking about. What engine? How many miles, etc.. What was the code from the CEL?