OK, so years ago I replaced just a 240 muffler, and realized it was a royal pain in the ass to do so without an acetylene torch. Figured if I just stuck with doing a complete cat-back, (or in this case, including the catalytic convertor), I'd be fine, with all new parts.

The old stuff came off in minutes. Cut the bolts in the exhast-pipe-to-cat clamp with a sawzall, and the rest came off easily. Then the problems started. First one was my fault - I didn't order the split triangle flange that fits around the exhaust pipe. So I had to take the exhaust pipe off the car to pound/drill the old bolts off that half, then buy bolts to mate to the new flange half on the new cat. Disappointing though, that when I ordered a complete exhaust system, Groton didn't point out that I'd probably want this part.

Then:
- couldn't slip the axle pipe onto the front muffler, and had to take the front muffler back off, in order to force in into place
- another joint (forgot which one) was even worse, because there was a flat spot, that I had to round out with needlenose vicegrips before it would go on
- the clamp specified by Groton for the front muffler-to-axle-pipe connection still "wobbled" when it was torqued down to its limit - too big. Had to buy a 2-1/8" guillotine clamp locally
- couldn't slip the tailpipe onto the rear muffler - not even close. Fortunately, had an exhaust pipe expander, and finally got the tailpipe large enough to fit over.
- and the final insult - I couldn't get the connections between cat and front muffler, or between axle pipe and rear muffler, to be leak-free. On the cat to front muffler connection, I used an impact wrench and with the clamp seemingly at its limit there's still a leak. On the axle pipe to rear muffler connection, it seems that the bolt stripped before I got an air-tight connection.

Am I simply putting the clamps in the wrong position? A guy helping me said put them right at the very end of the overlapping pipe, but I think this leaves the outer pipe split open about 3/4" back from the end, hence a leak. I thought it would be best to have the clamp back about 3/4" from the end so it completely closes off the split. Anyway, for most of the connections, no approach seems to have worked. And I figure that if I tried now to pull it apart and use muffler cement or something to fill the gaps, there's already enough kinking to prevent me from getting it apart.

I bought your generic guillotine u-clamps, and plan to add them and impact-wrench them down, in hopes of finally getting a seal. Would appreciate any advice on ideal positioning. I suppose I'll just have to leave the old circumference clamps in place, as I don't want to be sawing them off, and risk cutting into the new pipes.

Ironic part, is that when I mated the cc to the exhaust pipe, I couldn't see how the sealing wring I bought was supposed to fit. The exhaust pipe had the flare going inwards, and the cc had the equivalent flare going outwards, so I just clamped them together without the seal, that that appears to be leak-free.



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David Armstrong - '86 240(350k km?), '93 940T(270k km), '89 240(parts source for others) near Toronto