I had a lumpy cold idle and kept getting misfire codes and running rich code.

My mechanic said it's injectors.

While trying the sea foam throttle body spray, I started looking for possible vacuum leaks.

I started moving hoses to see if the idle changed or if I heard a leak.

Right in front if my eyes the supercharger bypass actuator hose had a large crack where it entered the supercharger. I checked the hoses on both sides and it literally crumbled upon moving it.

My car only has 34k miles and is 5 years old.

Cheap $6 fix for 2 feet of hose from autozone.

 

This is why people suggest to watch fuel trims. They will find even small air leaks.

Also, you can avoid seafoam and avoid paying anyone.

 

Can you go into details on fuel trim?? What do you look for?

 

Do you have a photo in the engine bay where this is? I get a little hiccup on idle sometimes but never throw any codes.

 

If you remove the engine cover you will see it right on top. It's just on the other side of the throttle body.

One hose runs to you intake duct and the other goes into the supercharger.

 

Yeah, I just changed my oil and saw it. My hoses are good still, 2010 with 82k miles.

 

It must best the Texas 100 degree summers.