Out of the blue my 4.6 will not run at closed throttle idle. Replaced IAC, TPS, CCRM, and ICM. Cannot find any vacuum leaks, I can fool it with a feeler gauge between idle stop screw and throttle return and runs fine. I used the actron OBDII and gives me a P1505 at times. I replaced the CCRM because I do not think the fan low speed is operative when it is fooled, and the idle correction when the air conditioning compressor is operating does not actuate. Any ideas?