usually when they go out (really out) the car will idle like crap - i
it idles at all - & will suffer from initial takeoff hesitation,
but (usually) wide open throttle doesn't show as many symptoms.
there are two basic kinds of egr problems besides a gaske
leaking...... 1 - egr not operating.  this one will throw a chec
engine light, but the car will run fine 99.9% of the time until i
does something like eat up an o2 sensor or something like that.  2
egr valve leaking when it's supposed to be shut.  this one will thro
a check engine light too, and this is the one that makes the car idl
bad, etc - because it is dumping exhaust gas right into the intake
at idle, regardless of throttle position due to a burned/worn valv
seat.  in either case, if the valve is bad in either of these ways
it should be replaced before it causes other problems.   other thing
can make the ecu think the egr is bad though - most noteably, a vacuu
not hooked up to the egr valve, or hooked to the wrong port, or th
vacuum solenoid that opens to deliver vacuum to the egr (possibly th
electrical connection you mentioned) is malfunctioning, not lettin
vacuum go to the egr, so the egr doesn't open.  if you have a vacuu
pump, you can apply vacuum to the intake side of the valve, the
using a jumper wire, hook that valve up to a battery & check th
egr for movement (or check the opposite side of the valve fo
vacuum)