Still picking up codes in my 1993 F-150 5.0 for the EGR. I just replaced both less then 100 miles ago.

 

the EGR doesn't work alone, it has controls. Follow the vacuum lines from the EGR and see where they stop. There is a relay-controlled solenoid at the other end that gets corroded and may stop the solenoid from working.
Anotherwards the EGR is vacuum controlled, a broken vacuum line will produce the same codes even if the EGR and relys are OK.


OR>>>> did you clear the old codes??? See Ford fuelinjection.com there is a simple procedure to erase old stored codes. Or you could disconnect the battery for a few minutes.

 

Also check the vacuum canister(coffee can). They are notorious for rusting and cause a leak there.

 

disconnect the battery for 15-30 minutes to clear codes.

 

That is not mandatory...just to be clear, it is better to use the procedure at fordfuelinjection to clean codes. all it takes is to disconnect the test wire during the reading of the continuous memory codes. Why wait 15 minutes or stress out your terminals and wires every time you need to reset?

 

There's another good reason not to disconnect the battery, doing so also wipes out the learning the computer has done on the fuel and ignition maps, and it will take some time and driving around to relearn everything. For some problems this can be a good thing, but on others it just makes diagnosis harder because the motor will behave completely different and it may mask the problem you're trying to fix, fooling you into thinking you fixed it when you really haven't.