Vanagon – jury rigged fix for deceased cat

This post might get me some guff, but please have patience, I will get a new cat. The catalytic converter on my van is old, very old. Recently I’ve suspected it really was a converter in name only. I took it off today and it was empty. All the rare earth metals and ceramic had blown out through my stainless muffler. Ok, so now what? I had the shell in my hands and I decided to do a little experiment before i hunted up a new cat.

I had this resonator muffler thingy hanging around the mess I call a workshop. It is a little longer than the cat but I thought I could slap it in place and  see how it effects the sound of the exhaust. Ok, here goes..

The resonator, 2″ outlet/inlet. I scrounged a 3 bolt flange and cleaned it up on the lathe. Bored it out a tad so it would fit on the pipe.


You see? Pipe set into the flange.


And positioned not quite all the way through.



While I was at the lathe I necked down a nut to act as a threaded bung for the O2 sensor. Man, I just can’t recall the size of that nut right now.


Tacked the flange to the pipe.


Then a mostly autogenous weld inside.


If you squint you could imagine that hole was roundish.


Necked down nut pushed in hole.


And a bit of a heavy handed weld.


Two slits on the other end (tubing fits over the tubing inlet of the muffler. The slits will let the muffler clamp squeeze the assembly tight)


During installation my new lover was pestering me. For the last few weeks this goose has decided I am something special. I really don’t know what is going on with her.


I had to slide the muffler over a bit to get the resonator installed. It does look a bit funny, I admit. And did it change the exhaust sound? Yes it did, it is a bit quieter, with a hint of raspy with quick throttle off.



  1. #1 by Pz on March 29, 2014 - 3:47 pm

    Hmmm, attracting female geese in Spring.
    You been using argon as a shielding gas lately?


    • #2 by albell on March 29, 2014 - 5:09 pm

      The goose is desperate 🙂

      yup, been using argon, why?


  2. #3 by Pz on March 30, 2014 - 8:55 pm

    Sir Ramsay who produced Argon in 1894 was an avid Duck raiser and collector of exotic species…
    You appear to have a similar effect on your duck while using Argon… even thought the Argon is inert…:-)

    • #4 by albell on March 30, 2014 - 9:30 pm

      Good grief, your jokes are as arcane as David B.’s


      Ramsay and I were born in the same city, only 106 years apart.




  3. #5 by Pz on April 2, 2014 - 12:49 pm

    Arcane… shoot, Alistair I knew that already.
    I was also playing on your common Scot roots..:-)


    • #6 by albell on April 2, 2014 - 7:36 pm

      My roots were showing? Gad, I need to get something to cover them up.

      BTW, what do you think of the beaver crossing? Search shows it is registered to Viking Air. One of their executive models?


  4. #7 by Pz on April 9, 2014 - 8:22 pm

    Any beaver crossing gets me excited!

    The viking air model…
    Hmmm, seen a similar paint scheme on a beaver up here.
    Sealand Aviation is a sub-contractor to Viking Air

    Thus… a ton of Beavers are in rework up here.

    About your Scotish roots?
    You seen or watched “Sunshine on Leith”..?
    Proclaimers Music, a musical then, made into a move…
    Watched the movie last night from the net.
    Was kinda cool, similar to Mama Mia…
    A move with song instead of dialog.


  5. #8 by Dan Beatty on May 8, 2015 - 3:05 pm

    Glad you tried this. I have a very short muffler setting on the shelf that I have been planning to install in place of the straight section of the “J” pipe in hopes of reducing the exhaust noise. It will need to be fully insulated so as to not loose too much heat.


    • #9 by albell on May 12, 2015 - 8:05 pm

      Hi dan,

      My set up is still running strong which is good as I’m still dithering about an engine conversion. It did reduce engine noise and I did try it on the other side of main muffler ( pushed on tail pipe) to see if there was any difference. It might have been quieter that way but it was more work to install.

      Hope it work out for you


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