codes 32 and 43 , 89' 350 need help

today i my truck threw 2 codes. 43; esc failure or knock sensor failure , and 32; egr failure. ive pretty much lost have of the power the truck use to have , im pretty sure this is caused by these 2 codes. what can i do to fix them , what can i check , what can i do ? just replace it all , how much is a esc or knock sensor. how can i figure out wich part of my egr system is failing ? maybe its a vaccum leak ? also when the truck idles for about 2 or 3 minutes the idle starts to flucuate. now my oil pressure gauge doesnt work , it goes all the way to 60 or whatever the guage's highest reading is , but when the idle starts to flucuate the oil pressure gauge moves ? i finaly got the water pump thing straightend out now id like to get it running better. i really need you guy's help. thanks

chris aka fattie

The Esc Stands For Electronic Spark Control Its Incoporated Into The Ignition Module In The Distributor And The Ecm.when The Engine Starts The Module Controls Spark Timing For A Predetermined Amount Of Time Then The Computer Sends A Bypass Signal To The Module To Allow The Computer To Take Over.you Need To Check For The Signal If You Have It It's A Bad Module If Not It A Bad Ecm