Did you replace the EGR or PCV valves?

In the old days the recommended time and mileage to replace the PCV valve was every 12 months or 12,000 miles. I still do that. My 08 Grand Marquis has a heated PCV valve and I still replace it once a year. The EGR valve, as far as I know, has no service interval. In fact, I've never replaced one on any of my vehicles. I've never removed and cleaned one either. The EGR valve is one of those things that either works or it doesn't. Hope that helps and good to hear from you again! Jim