is the rule of thumb of 4 years really true with Stock systems?

Usually every car I had I throw that stock **** away right off the bat.... but with my 2001 protege should i expect it to go now, I am timing it with a Borla upgrade soon.

 

My wife's mustang is a 99v6 with only 65K miles and it took a crap on her last week. She's now riding on a Brola side exhaust off a cobra R. I'll have pics and video tomorrow if I can find someone to host them.....(wink at BatmanG)

 

a lot has to do with driving habits.if you get in your car and drive it 40 miles or more on the highway to work every day it wil last way longer than grandma driving 3 miles to the store and bingo then home because it will heat up completly and burn off all the water condensation on the inside of the pipe that comes from normal engine exhaust.also if its parked on gravel or stone instead of a paved driveway makes a diffrence.moisure from the ground comes up from under the car on stone to attack the underside of the car exhaust included.id say at least 6 years give or take the conditions