Muffler rebuildable?

[TechMOGogy]

PO put an EI SS muffler on and last Friday when going to get licensed I had a backfire (issue with my O2 sensor and running to rich) and it seems to have blown a baffle or something in the muffler! Sucks! It is much louder and there is a metal drumming sound (like hitting loose sheet metal).
I know a custom muffler shop and wondered if they can cut it open, repair and TIG back together?
I am not sure how the muffler is assembled so not sure where they should cut etc.
Just not overly wanting to buy another new one at this point if this one can be fixed.
Thanks for any advice/tips and I have a ticket in with Scott as well

[rmel]

I'd be surprised if this was related to your O2 sensor.

Your ECU should be set with the O2 sensor NOT being
used to moderate the amount of fuel injected, it should
be 100% table driven only. The O2 sensor should be
simply a monitor of AFR.

Even if it were on, typically the amount of increase/dedcrease
fuel injected from the look-up table value is limited to ~20% or
less. But again it should be OFF.

IMHO you should take a look at your ECU setup to make
sure it's configured properly.

Did this happen at cold start? The ECU will look at the engine
temp and when cold ADD a considerable amount of fuel vs Temp.
to help start the engine, maybe that's set way too rich.

ron

[Haf-e]

Sure it can be cut open and rewelded - and it would be worth the cost of doing that compared to buying a replacement.

Glad you are giving scott a chance to consider warranting it as well. Let us know what the outcome is.

[TechMOGogy]

Yes I need to look at the ECU as I am not sure how it is setup.
It will have Jim's latest map (as of a year ago) but I still need to take a look and discuss with Jim.
O2 sensor was more of a guess as it did have the broken wire from my other post.
Temp outside was about 40 degrees, truck had idled for 5 mins and I was driving for about 5.
I have a current issue where when coming off of higher RPM, ie coming to a stop sign, when the RPM drop it stalls.
Older laptop with serial port headed home tonight so I can start taking a look.
Updated ECU and O2 senor in other post.
viewtopic.php?f=12&t=10658
Thanks,
Dan

[TechMOGogy]

Sure it can be cut open and rewelded - and it would be worth the cost of doing that compared to buying a replacement.

Glad you are giving scott a chance to consider warranting it as well. Let us know what the outcome is.

I'm not sure about warranty as I did not buy it but did ask Scott the same question as I posted here - can it be rebuilt and if he had any interior/cut away pics of the inside.

[Jimm391730]

I had the same problem -- a backfire loosened the baffles enough to create quite a rattle. I cut a rectangular opening along the length of the muffler about 3-4" wide, spot welded the baffles to try to quiet it, then brazed the panel back in place. Worst case, you might be removing a panel that still had a good weld to a baffle and then you might get things bent when opening it up, but you will still be fixing it and sealing it all back up again. I didn't have any SS wire to weld it with so I brazed it (the bronze won't rust, either).

[TechMOGogy]

Scott got back to me and put me in touch with the manufacturer
I would never believe it unless I was there to test it myself - no issues, it is 100% harmonic reverb from the back plate!!
Newer ones have a piece welded across it on the inside to stop this. I will just have a small 1x1 channel welded across the outside to stop it. For now a piece of wood is jammed in there and is working perfectly
Easy fix and like I said I would have lost a ton of money on it!
Cheers,

Edit: forgot to add that the manufacture offered to repair my muffler even though I was not the original purchaser. Now that's a warranty!! Manufacture is a great guy and nothing beats a direct call from the company making them!

[TechMOGogy]

Just as a follow-up here is how the muffler reverb was stopped
SS rod welded to the rear plate.

IMG_7390.JPG (112.23 KiB) Viewed 3734 times