4 years ago I had to do the head gaskets on my 2008 Subaru Outback. Now, 30,000 miles later they need doing again and I need a new catalytic converter. The car only has 132,000 miles on it but it’s pretty much covered in dings, dents and such like. I’m looking at $4,000 for these repairs and I’m due for a major service and new tires. I’m not sure if I should proceed as it’s really frustrating to be doing the head gaskets again. Is this something that is going to happen every 4 years? TIA. 

56 minutes ago, dlm5774 said:

4 years ago I had to do the head gaskets on my 2008 Subaru Outback. Is this something that is going to happen every 4 years? TIA. 

No. They weren’t done right the first time.

If you don’t have a good shop then headgaskets and P0420 code (“converter”) might not be worth paying up and working through on a beat car. 
 

A head-gasket job in my neck of the woods is like $2k using AISIN timing and fel pro multi-layer HG.  I have never had to replace a catalytic converter at that mileage.  O2 sensors, sure, but  doubt it is really a converter.  I could be wrong, but have them replace the proper sensors and check for exhaust leaks, etc first.  Find an independent subie shop in your area and your price should come down and your quality of install will probably go up. Once you get a more competitive price, you can figure whether you should kick it down the rod or not.  I do agree with idosubaru that it was probably not done right the last time.  My first HG repair on a 2000 subaru was  in 9 years ago and it is still humming away with my son driving the daylights out of that one.