A year ago my mechanic told me I need to replace my catalytic converter. He used an aftermarket unit and gave me a one year warranty. 11 months later my car failed emissions for nox. He looked at the report and immediately said, "you need a new cat. I'll replace it under warranty." All good, right? Except the new cat is so noisy. It rattles, it sounds like the car has some kind of hot rod exhaust. BTW, the car passed emissions. But I can't stand the noise. He is bugged at the cat supplier because they wouldn't back up the warranty and he ate the cost, without complaint.

Now I'm going to have the work done again--probably by my mechanic. I'm planning on going ahead and putting in a volvo cat. what do you all think of this? On the cheap aftermarket units, I've two bad ones in a row and am sick of the hassle. My original one last 120K miles.

Oh, also, is the Miller the OEM unit? Or just a more expensive aftermarket unit?

Thanks,