Yes they were intended to be lifetime replacements but MB only warranted the replacements for only 12 months/unlimited mileage. You can take take that for what its worth. I've heard of some people fabricating a straight pipe instead of having the oxy cat and I have heard of other people just converting the entire intake/exhaust set up to a 49 states system. Personally I like the 49 states set up because it frees up a lot room under the hood and gives you an extra 5 hp over the CA set up. The straight pipe might do that also but I don't know for sure.
It's your car, it's your choice.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012