Erroe code po405 on my car - Focus Ford Cars & Trucks

Hello.
The error code PO405 = EGR, ( Exhaust Gas Recirculation ), sensor A circuit low input.

What the EGR does;
EGR = Exhaust Gas Recirculation system
Recycles small amounts of exhaust gas from exhaust system, 8 to 10 %, and mixes it with intake manifold air going into the combustion chambers. The addition of this inert, or non-combustable exhaust gas limits the peak combustion temperatures to a range that is below 2,500 degrees F, where the formation of nitrogen oxide, ( NOx ), is known to occur.

Here's a picture of an EGR valve to help you locate yours
You may find that you just have a lose hose, or you may have a small vacuum leak.

I hope this helps you.
Donnie