Recurring P0401

Replaced EGR;
cleaned all lines (EGR to VSV, EGR to VR, lines to air intake manifold;
ohms tested satisfactory heat sensor at EGR/intake manifold.
Lightly (with qTip) cleaned out intake manifold orifice connecting to EGR.

Next? Replace Vacuum Regulator VG? Replace Vacuum Switching Valve VSV?

Suggested to "scour" w/22 rifle brass cleaning brush intake mainfold orifice?

Tacoma has 220k miles and previous owner was spot on with maintenance!

 

For me, I had to remove and clean the EGR temp sensor. Then the 401 would go away for about 6 months and then finally come back. Clean again, etc.

 

Forgot to mention that I also thoroughly cleaned EGR gas temp sensor b4 ohm testing cold (200k ohms) and after engine warm p to 120F (87k ohms).