i took my intake manifold off to install the direct port kit, and i came to find this.

Cylinder 3 is perfectly clean in my intake manifold, and in the intake port in my head. pulled a spark plug to find that it was a lot cleaner than 1,2, and 4.

what is causing this? car is not breaking up/detonating. It is running perfectly fine.

here is a pic for reference:

 

It runs perfectly fine?

 

yes it runs better than ever.

 

maybe have your injectors flow tested and cleaned?

 

i dont think it is running lean, the car runs perfect.