(2000,Camry,2.2L,auto)
Wanted to share what I found with one of JohnGD reply's EGR Vacuum Modulator Valve on Gen. 3 Camry - Toyota Nation Forum : Toyota Car and Truck Forums over at Toyotanation...Thx,John..
"P" port at throttlebody completely blocked,"R" port at throttle body partially blocked,I had no vacuum at "Q" port at the EGR vacuum modulator,tried to use a small wire (port tubes are curved),was able to make the curve but could not make it threw the holes in TB....used CRC throttle body cleaner and the spray nozzle,forcing cleaner threw the ports,then used rubber tip air nozzle using moderate air pressure to blow out the ports,alternated cleaner and air to clear out ports,reattached hoses and checked vacuum at "Q" port at modulator,eng RPM at 2500 and had 20 in/Hg.
I had previously cleaned the TB and my assumption is that i inadvertently plugged the ports when cleaning.
So if you clean the TB and and you get a CEL,and the code is P0401,check these ports...