I have two problems with '95. Could they be related?

1 Idling rough and surging at low rpms and at idle. It can also be difficult to start. I've replaced the TPS to no avail. I had this exact same problem three months ago. I let it go for too long and the catalytic converter clogged and had to be replaced. A mechanic found a bad spider injector and replaced that too. He believed that to be the source of the clogged CC. The car was running very well until recently.

2 Leaking coolant from the waterpump/plenum gasket on occasion. I'm having to add coolant about every five days.

I'm worried the cat converter will clog again and am desperate for some solution. I've also replaced the TPS and checked vacuum lines to no avail.

Any help would be great. Thanks.

 

For anyone who's having the same surging/rough idling problem, I figured it out via another post. It was a stuck EGR valve. It seems to be a common problem with 95 blazers. I took it out and cleaned it really well with carb cleaner. She's running like a beaut.