i'm wondering what kind of life expectancy aluminized cat back systems usually get. i had one on my '03 and the muffler rusted out in about 3-4 years (if i remember correctly). then i put a stainless muffler on. but the tubing never rusted out.

 

Depends on the amount of salt on your roads in the winter months. If none, aluminized is fine and holds up well unless you just want to fork out the extra $$$ for stainless.

 

The aluminized chambered mufflers rot out faster than the exhaust piping because when condensation and water gets to the muffler, it rusts and humididy takes a hard toll on the interior also. Even when the exhaust gases and flow is passing through water is still taking a bit to dry out from inside.

 

^ Yep, "chambers" are excellent for trapping water!

 

We get very little, if any, bad winter weather where I live. Aluminized pipe has held up fine for me, but the aluminized Fartmaster that I had taken off a couple months ago wasn't in great shape. Started rotting at the seams because of how the chambers trap moisture.

 

I have used both stainless and aluminized mild steel, I live next to the 2nd saltiest body of water on Earth and our roads are HEAVILY salted with salt and salt slurry mixes....... and aluminized holds up fine here. I have friends near the Great Lakes, and it rots off of their cars in a decade.

I'd say it would depend more on average humidity.

 

My aluminized pipe looks way better than my stainless magnaflow or stainless headers which all have the same age on them. This is south Texas weather and a lot of time spent on the beach with salty air and water.

 

You pretty much answered your own question. I got 4 yrs out of mine and I'd even wash it down here and there. Those 4 yrs were average for winter salty roads, rain etc for the great lakes and it rotted pretty bad. I've had a stainless since 2005 and it's still fine.

 

experience here in south florida has 6-8 years on piping, it starts to rot, mufflers tend to last a little longer...