Hello
my father bought this GMC sonoma 97 v6 4x4 5sp few months ago from a kid who slam headers and full exhaust before his spider went so we got it for great price, got a new spider and it ran fine. but it loves burning the wires causing coil to spark but other then that drives great

till it started throwing codes first was all four o2 sensors at once we clean it with a scan tool and it didn’t come back then MAF code we did another clean and it was gone too then TPS threw and we clean it and it also never came back during all these codes motor ran great so we just kept cleaning and wondering why it was triggering the codes but now while driving once we hit 30 mph the rpm goes to 2500 and stays there till we stop giving the code p0507 we have a blazer 97 4.3 auto for parts that was parked running good so we changed IAC, TPS, and it still does it we notice once we remove the vss from transfer it stops i was hoping some one else had the same program before we start dumping money on parts that might not be broken we beginning to think it the ECM

Edit: we also already check EGR , Vac leaks, it doesn't do it was IAC unplugged. we tried blazer ecm that for a auto it makes motor miss but with wheels jack up it still does it at 30mph

 

Have to think on your major problem - But I do have a tip for you and others with headers and burning up plug wires - Pick up some 3/8 fuel line, cut 6 inch long pieces "longer where needed" and split the side open and apply over the plug wire with the split facing away from the header, slide down to the boot on the plug, the fuel line will insulate it from the heat eating the wires, I've had the same ones on my 350 Chevy powered RX7 for three years now