runs rough at idle with a noticeable vibration?

My astro runs rough at idle with a noticeable vibration and it has now failed emissions. I have cleaned the EGR valve, the CPI module was replaced a few years ago as was the plugs, wires, and distributor cap. There was a rattling sound in th cat prior to this issue that has gone away. I have had the injectors cleaned by the shop. He did say my wires were looking tired again. I'm going to try plugs and wires, but the severity of the vibration and emissions makes me skeptical.