I just received my throttle body back from Proflow and I am curious about the "primer like" coating they used on the back of the butterfly and air flow path. Is this to make a complete seal when closed? It seems a little "cheap" and uneven.

Should I just leave it alone?

 

Shaner > Yes, that is what the gray coating is used for. If you remove this coating it will cause erratic low speed idling. It is impossible to get a 100% perfect seal and that is why Proflow used it. It does not hinder the performance.