Ok. Well first off my engine has been lacking power and the rpm's dip everytime i come to a stop or slow down close to stopping. (About 400 RPM's) They will pop right back up, only dipping for a quick second. It also does it when i turn the wheel which i think is fairly normal but not this low to where it's ready to stall. I've cleaned/checked the... IAC, EGR, MAF, Throttle body, Air filter, And ive also sprayed carb cleaner along my hoses for a vacuum leak. Also when i turn my engine off i've been hearing a buzzing noise coming from my EGR valve solenoid. i took the vacuum hoses off and cleaned the solenoid a little bit and the buzzing has stopped after shutting off the engine. But i am still having the lack of power and dipping rpm's. ANY HELP WOULD BE GREATLY APPRECIATED!!!!!!!

My truck is a 1997 f150, 4.6l triton V8. ext cab 8ft. bed.

 

That's bad... I have the same issue on my truck too. 2007, 5.4l. I did the same as you clean. The rpm at Park or neutral is around 650/700 when you past to drive or reverse it go around 500 nearly 450.
only when the engine warm up.

And when i'm running on the fourth gear o/d on between 57-70km/h the engine give some shake.. like is missing gaz, or missfire. No code.
Around 130 km/h the rearview miror is buzzing, at 140km/h notthing..
Maybe a tranny problem, but it seem to shift good and downshift well.never miss any fluid in it. that truck did not work very hard like towing a big trailler or whatever. just a good payload of sand

Thanks

 

i had an 88 f150 with what sounds like to be the same problum. in the end mine was just a worn out cap and rotor. its worth a shot to take a peek at it and maby give it a cleaning.