i have a 1997 ford f250 xlt extcab 4x4 i bought it cheap because it had a blown tranny so it had sat for about a year had old tranny rebuilt and got truck running it had miss fires and rough idle so i changed the 8 plugs and ignition coil pacs it fixed miss fires but it still has rough idle and low power i thought maybe it was the old fuel so i changed the fuel filter and ran premium fuel with injector cleaner ive ran about 2 tanks worth and so far it seems to run the same i hooked up a scaner and it had lean codes any help would be appreciated

 

Not sure that I had exact problem, but was a similar problem. Mine would have a low idle and then stall, intermittently. It turned out to be the Idle Air Control Valve (IAC Valve). Just do a search on troubleshooting it and that should help you solve it or eliminate it as a source of your trouble.
Good luck

 

Clean MAF sensor, check for vacuum leaks..as well

 

checked iac it was pretty clean slight carbon build up only on the inside walls so i blew it out and put it back no difference noticed in performance looked at the maf from the airfilter and wires all looked in tact and clean a friend told me something about the egr so i checked that to and it seemed fine checked the vacum lines i could acces and all seemed in tact and clear in the insides of any blockage

 

Have you hooked up a vacuum pump to your egr valve while running and pumped it a couple times ? Should idle rough and or die if the valve is working properly and if theres no change in how it runs then you need to change your egr valve out. Have you checked the hoses from your DPFE sensor that run to your line ?

 

tested egr by taking it of the truck hooking up a sucking tool to open it and running compressed air through it to see if it made it to the other side it did fine and idk what the other thing u listed was could you plz explain

 

sound like a vacuum leak(s)... check for split elbow(s) under the intake manifold

 

what would those vacum lines be connected to like do you have a pic or somethin because i checkd all the 1s i could see i think i missed sum like where exactly are those lines

 

Had a similar problem with my '97. Changed out the throttle body and all is well.

 

throttle response sucks for the most part but it still not enough to where i think it would need replaced what was yours doing that you had to replace it i'm gonna clean the throttle body now thanks for the idea