grillage

I replaced the middle muffler and have not been able to get an airtight seal on the the clamp that connects the y pipe to the middle muffler's pipe. (#17 in this photo)


I've retightened a couple times to no avail. Also tried some super high temp silicone stuff.

I think that at some point my cats have been replaced because there is no hanger between the two and because the whole exhaust sits about 2 inches off center toward the passenger side. This caused my original middle muffler to pull off of its hanger and break.

The cats....


So anyway, I think I should just have someone weld the pipe together at the middle. While I'm at it should I remove the cats? I'm in Ohio which is a state without emissions testing so that shouldn't be an issue. Are there noticeable performance gains from such a cat delete?

GuyllFyre

Those are definitely aftermarket catalytic converters welded in place of OEM.
AFAIK, there aren't any major gains from the CAT delete on the 12V V6.
Mine actually seems to run better with a new pair of Magnaflow clamped in place with new O2 sensors instead of the straight pipe that the PO had put in place of them.

As for the clamps, I used some muffler pipe seal paste but my wide band clamps seem to seal fine without, it's only the spots around the regular clamps on the cats that leaked.

Loudgoldwing

I had the same issue when I did mine. The reason for the seal breaking was because of the lack of a FLEX PIPE between my "Y" pipe and the Cherry Bomb Glass-Pack that I installed as a resonator replacement for my shoe-box middle muffler.

I have since cut off an additional 8 inches of junction after the "Y" pipe, and installed a stainless braid-covered flex pipe to connect the "Y" to my Glass-Pack. The flex pipe absorbs engine vibration, and more importantly, allows for the natural tendency of the engine to shift on its mounts when transitioning between acceleration and deceleration.

As an added bonus, there are no longer any feelings of "engine shimmie," or "buzz droning" because the flex pipe absorbs and cushions against vibration.

This is what you need:



Buy a flex-pipe with 2 1/4" inner diameter. You will need to notch and flare it on one end in order to fit it over the metric "Y" junction.

REMEMBER, Grasshopper: The key to successful exhaust installation is NOT HAVING TO PUSH, PULL, OR TWIST any of your pipes to make them fit, as you install from front to back. Having any unresolved tension will result in exactly what you are experiencing, or worse, a cracked pipe or cat. Having a flex-pipe give you a measly 3-degrees of flex at the front of your system will ABSOLUTELY result in the freedom you need to move your mid over the 2 inches you require without exerting the damaging tension on your "Y" pipe and cats.

Loud pipes save lives. But cracked pipes sound like ***.

Cheers,
LG

grillage

Thanks for the insight guys, I am pretty sure that the problem lies in the off-kilter-ness of the y pipe being aimed slightly off line from the mid muffler. I thought about a flex pipe too but I wasn't sure how well they worked - I'll bet that is the best bet. Right now the whole system is under a little tension because of the sideways lean of that y-pipe. I'll look into a flex pipe as the solution. I only thought about the cats because I would theoretically have a guy with a welder there anyway.

thanks

grillage

Also, LGW, did you have to weld that flex pipe in place or would clamps work?

grillage

Never mind - it looks like you can buy them for welding or you can buy them with a couple inches of pipe attached so you can clamp...

Loudgoldwing

Mine are clamped, with some good Permatex muffler & Tailpipe repair paste slathered on each of the surfaces before mating them.

IMPORTANT NOTE: Get each of the mating surfaces wet with water before putting the paste on and clamping. I KNOW... just do it. You'll thank me later.

grillage

I took everything apart and my rear muffler was like a castinet. I turned it over and it barfed this,,,



When cats break how do they come apart? I remember my first car - a 1979 Rabbit - had the cat guts come loose and It was a serious problem.

Should I take the pipes apart and take a look?

I guess this would be as good a time as any, I just replaced the down pipe studs and nuts when I did the heads a couple weeks ago. I won't have to fight with the nuts and bolts much

GuyllFyre

That is the guts from at least one of your cats.
Time to replace them and dump out anything stuck in the mufflers and pipes.

Andy1212

What do you guys recomend replacing the cats with? I think mine also need to be replaced, but i obviously dont want to spend the money on a new cat from the dealership, and i also am leery about aftermarket cats because i dont want it to sound like ****. Any suggestions on an aftermarket cat that wont affect the exhaust tone/volume to significantly?