For better or worse, I have decided to do what most people do-- buy a new EGR valve. There are too many factors to control, especially since the car has an undocumented history, to spend more time experimenting with a used, questionable valve.

I went with this product--
https://www.rockauto.com/en/moreinfo...choice=0-0-1-1

Thanks for all the helpful discussion-- that helped me decide what do do.

That'* cool. I've heard good about Standard. Haven't used them myself. Curious how yours goes in say a year or two.

We had a guy here years ago make an EGR stove pipe to prevent intake from melting. THIS was the only work around besides deleting and blocking off your EGR.

I believe it. It was a bad decision to push hot exhaust gases through plastic. Very bad.

Too bad I didn't still have my 95. I could take it out and measure it.

I have had 2 of these problems on a 98 Park and a 99 LeSabre. The new aftermarket plenums have a smaller stovepipe that protects the plastic from temperatures. The first one was found after a head gasket repair and the mechanic missed it even after I warned him about it. Cost me an extra $250. The second one I found after coolant was blowing out of the cylinders! I flushed the engine and replaced the manifold myself with a $100 kit off of eBay. That was 30,000 miles ago and still running strong.