I have a 90 xj that high CO's are preventing smog pass. I know a faulty egr may actually reduce CO's. but my question is this: what would cause the pintle on the egr to move slightly at idle? The egr does everything it's supposed to while testing it. Their is a surge in the idle that revolves with the egr moving ever so slightly. When I pull the vacuum line either from egr or its solenoid the surge and pintle stop and it idles smoother and higher. If I'm correct the (b) port side of the egr solenoid shouldn't have vaccum after detaching and and reattaching the electrical connector. And it does. It has vacuum no matter what. So is this likely the culprit? Or is it more likely the egr is too dirty to close all the way and stay closed when it should be. Thanks in advance for any input. Also, put in a new map sensor and new cts sensor. The jeep seemed worse after this. But only when engine is cold. I don't have the smog numbers with me, but the CO's were around 8.-9. The o2 sensor, cat, air/fuel filter, plugs/wires, cap,rotor, are new as well.