[Diy_efi] Re: Can constant WOT operation destroy a muffler?

[GuitarCrazyJim at aol.com]

Does this particular brand of muffler have a weep hole in it anywhere, like 
on the back side not shown in the picture?  From the general rust appearance it 
would seem your in a colder climate than here in Phoenix,AZ.  Even here, but 
especially in colder climates, I have seen where mufflers have worn out do to 
rust from the inside. 

Due to heat generated from the exhuast, especially the Cat, the metal does 
heat up.  When you shut the engine down the heat will cause the moisture in the 
ambient air to condensate out and onto the metal.  This is especially true on 
the inside of the exhaust pipes and/or mufflers.  Ever noticed a car in cold 
weather when it first starts up in the morning blow water out the tailpipe? 
That's where that water comes from.

Some muffler manufacturers put a weep hole about 1/16" to 1/8" near the 
bottom of the muffler to allow this condensation (water) to drain out thus slowing 
the rust action.

Just my 2 cents.
Jim