I have a 2000 Ford Escort that runs pretty well, I think, but my wife says it lopes erratically at an idle and sometimes stumbles as you go. OK, and there is that whole Service Engine Soon light. I had the Autozone guys run a computer check on that light, and it came back EGR - Excessive Flow.
Does this mean I should try to replace the EGR valve? They suggested it might just need to be “cleaned”.
If the EGR valve is dirty or worn, and cannot seat properly, then yes, this will behave just like a vacuum leak. And, the symptoms of loping at idle, and stumbling as you go are typical for a vacuum leak, like a broken vacuum hose or an intake manifold leak. Yours just happens to be a bad EGR valve. Since a new one costs about $60 for a Motorcraft brand, according to www.rockauto.com, I’d replace it.
There’s a couple of things that can cause this code. The EGR valve pintle has carbon build-up and isn’t allowing the EGR valve pintle to close completely. In this case remove the EGR valve and inspect/clean it. The other thing that can cause this code is a defective EGR vacuum control solenoid. This solenoid takes it’s commmand from the computer as to when to apply engine vacuum to the EGR valve diaphram. For this, after the engine has reached operating temperature and at idle, disconnect the vacuum hose from the EGR valve. There should be no vacuum at this hose under this engine operating condition.
Tester