EGR Valve Insufficient flow

My 1996 Buick Century has now set a code : EGR insufficient flow. After it heats up (when the MAP sensor detects enough pressure to kick on EGR) My cars starts to idle rough, and if I hold the gas pedal down a little and let off, the car sputters. The Haynes manual says these are classic symptoms of EGR problems. I have already taken it off, and no leaks were visible, and carbon buildup was minimal - in the intake, EGR tube, and on the valve itself. the gaskets were also in good shape, but I replaced them anyway. The code came back, naturally, as there were no leaks. My question is this: Should I replace the EGR valve next or is there some area I should also look?? Does anyone know of a test I can perform on the EGR valve to see if it is faulty? It has no vacuum lines - digital type with 3 solenoids inside. Thanks for any help

If there is no carbon build-up that is blocking the passageways then the valve will need replaced, especially if it has already been cleaned. These valves do go bad from time to time. I would purchase a used one rather than a new one, car-part.com will allow you to search for one at wrecking yards in your area.

You may want to clean the valve again just to keep you on the road until you replace it. Cleaning it may buy you some time.

I gave some misinformation on my vehicle. After purchasing the GM shop manual from Helm, I found that the EGR is the linear type with a pintle position sensor. Is it possible to take the EGR apart to clean it? There is a hex head on one of the valves - I am a little cautious about removing it though - probably going to buy a new one and a carbon catching gasket.:banghead:

It isn't possible to take it apart to clean since the positioning of the components is critical. You can clean this one just like the digital one by spraying the external components with throttle body cleaner. Don't forget the passageways either. One critial thing. Don't move the pintle or it will get out of adjustment. A new one may be the only recourse.