JerseyThursday

There must be something about the way moisture condenses in the rear muffler on 4Qs. I swear you could have the thing made out of titanium and it would start to rust in six months.

AudiSport4000

I think even in salt areas it will still rust.

gmbchef

Most likely its only the pipes that are stainless, not the muffler boxes. Thats the way the factory urq exhaust is anyway.

CGTBrad

Could be low grade stainless. I've had tons of cheap 'stainless' fishing knives rust to nothing.

PJM99

Could be cheap stainless plus, condensation builds up in there and mufflers don't last long. But most likely the muffler is not stainless, just the pipes.

cuatrokoop

Ti doesn't rust, really doesn't even corrode...

Anyway, I've had a Stebro for 5-6 years. It still only has surface rust on it. Roads around here get salted December through March, which will accelerate the rust. Most 300 series AISI steels will rust. A 400 series is generally more resistant. A 400 series will still rust though. Corrosion is also affected by which alloy they use in a given series.

"We offer quality stainless steel exhaust systems and tips for a wide variety of cars. Stebro exhaust systems are made from 439/304 stainless steel. Tips, flanges, internals and hangers utilizing type 304 SS while pipes and shells are type 439 SS."<ul><li><a href="http://www.scielo.br/scielo.php?script=sci_abstract&amp;pid=S1516-14392003000200012&amp;lng=en&amp;nrm=iso&amp;tlng= en">Comparo of AISI 304 and 439</a></li></ul>

Cdn Blue Coupe

Most stainless exhaust parts are only clad. ,,so damage it and it rusts!. Also the type of stainless is significant. 318 is usually the prefered stainless to resist salt water.

Just remember stainless steel is not stainless

jcs182

Ask any boat owner about their stain-less.