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Cat Converter miseries 850

I finally overcame my native inertia and started to replace the rattlebox
that my cat converter became. I had given several weeks treatment of mystery oil on the four flange bolts, and after the first one came out with some help with
a torch, the second bolt head simply snapped off. The next two didn't seem to want to go anywhere so I soaked them some more and went to the rear clamp.
I couldn't tell what fasteners were used on the two part clamp, where the bolt
head would have been there was some ugly rusted cone, resembling a dunce cap.
So lacking a cutting torch I cut the thing off with a Dremel tool.

Then I had a pleasant interlude putting in a new gas filter, and couldn't see
where people had trouble there, it went in easily.

Then back to that evil cat converter... I had unplugged the front sensor and now
I went hunting for the rear sensor. This is the bad part: I unbolted a cross member below the tail end of the cat and of the 4 bolts which all turned easily,
two just started spinning. Ach! Can I reach these things from the floor inside?
They look like some hokey arrangement where the female nut is just staked into the floorboard sheetmetal? and you cant get a wrench on the hidden nut!
Grrrr I'm PO'd! What to do?

Whats the story with the connection between the cat and the muffler?
I cant see if they just butt up to each other and simply split apart or one
piece slides into the other or what.

Where is the rear cat converter plug?

Now I don't know if I should go out in my comfy driveway and get the rest of those SOB flange bolts out or to have a lengthy lunch complete with a few frosty ones? A tough decision! :-(

Bill








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    Cat Converter miseries 850

    On our '95, the muffler slid slightly into the cat pipe. Not much - maybe a half inch or so. The connection is kind of like a flare fitting connection. Never saw one like that before. Anyway, the clamp fits around the flare joint. Don't be surprised to find that both the muffler and the cat have rusted through at that flare connection. That's what I found and had to cut both ends and patch it together with a 2-1/2"(?) coupling. It still leaks, but is better than it was and didn't cost anywhere near what a new cat + muffler would. A muffler shop could do a better job, no doubt.

    I didn't take the crossmember off because I wasn't changing the cat. I suspect the second O2 sensor is hiding above the crossmember somewhere.

    If it is hot laying on your driveway, then yes, go grab lunch and a few cold ones. Try again tomorrow.
    --
    "Differences of opinions should be tolerated, but not if they're too different' - Sharon Craig








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      Cat Converter miseries - Part 2 (long) 850

      I didn't need to remove that cross-member at all, there's just a little plastic clip to pull that holds the harness for the rear sensor which sits above the cross-member. I sawed off the tail end of the old cat just forward of the cross member and the old cat came out OK. Then after removing the rear clamp with a dremel tool, the stub was welded to the muffler. Things seemed pretty gloomy
      until I heated the junction cherry red with MAPP gas and put a 14" pipe wrench
      on the stub and voila'! (I was careful to avoid having that hot thing land on me!~)

      Now I snapped one of the studs in the flex pipe and tried to heat and remove, but
      there was little room to swing vise grips so I decided to reassemble with three
      instead of four studs.

      The next disaster was when trying to remove the plug for the front O2 sensor in my Bosal Cat Converter.
      First: I got the Allen key and a ball peen hammer.....nope
      Second: I got the BFH (32oz ball peen which usually convinces stuff)... nope
      Third: I heated with MAPP gas and used the BFH......nope and now the allen key
      and the socket head are starting to deform GRRRRRRRR
      Fourth: I took it down to my mechanic Guru and he tried moving it with a
      combination of of an air chisel and an Oxy/Acetylene torch...it
      did budge a tiny bit, but still no joy
      Fifth: we drilled out to 1/2 ' the largest drill bit we had and while
      he was looking for the right tap drill for the 18MM thd, I took
      it home an used a saber saw to put two cuts through at 180 deg. and
      knocked the remains of that SOB out.
      Grrrrr! I expected that the way my luck was going, that a giant meteorite
      the size of a Volvo was about to strike any second.

      The rest is boring, It all went back together uneventfully.
      The Wagner clamp was crap, so I reused the original clamp with some new bolts
      and the joint is noisy. So I wonder if there's a trick with that clamp, maybe using muffler bandage or muffler cement or something?
      Tomorrow I'll see if it passes state inspection, and find out about the noisy
      junction- Cat to muffler.













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        Cat Converter miseries - Part 2 (long) 850

        Put some muffler bandage around the tail pipe portion and stick it back together and clamp it back down. I am surprised that the tail pipe doesn't have a slight flange on it, like the turbos have.

        --
        My name is Klaus and I am a V♂lv♂holic








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          Cat Converter miseries - Part 2 (long) 850

          The end of the cat has a machined ball, and that mates up to the input of the
          muffler that has a small flare. The clamping arrangement seems weak mechanically
          but the good part is that it will come apart after years of rusting.

          The Bosal clamp sells for About $22 , and the Wagner is $7.
          The Wagner clamp has very small diameter bolts, ridiculous! Another hosing from Autozone.









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      Cat Converter miseries 850

      I figured out the lengthy lunch part easily, its upwards of 90F in the driveway!
      Hot for Boston.

      I followed the rear O2 sensor back to a plug next to the front sensor plug,
      the plugs are in a nasty location under the brake master cylinder.
      Now I wonder if the front and rear O2 sensor plugs can get reversed?
      Hopefully the plugs are different.

      Now I'm off to put heat on the remaining stuck flange bolts and see if my luck is
      consistent today. Pray for me! :-)

      Bill








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    Cat Converter miseries 850

    Times like this you wish you had an electric impact gun. It makes the job so much easier with rusty bolts.

    Both sensor connections are on top of the tranny, next to each other.

    The tail pipe fits into the cat, but the fitting looks to be quite loose until you secure the clamp. I had a helper push the pipe into the cat while I tightened the clamp.

    The cross member... no help here.
    --
    My name is Klaus and I am a V♂lv♂holic







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