One of my friend call me this morning and said his throttle cable gets stuck when he press the gas pedal (2005 Civic Si). I went to take a look at it and the throttle valve seems to move smoothly, so that wasn’t the problem. When I get in and take a look at it, I hear this noise (sounds like a zipper closing) when I press the pedal. It seems like the throttle cable gets lock at some point but I really cannot figure it out. My prediction is somewhere near the firewall but I’m not too sure. Anyone ever had similar problem?

It could be a defected cable or spring but I wanted to get some advice 1st before I start any work.

 

Anyone?