A year ago my mechanic told me I need a new catalytic converter. He installed an aftermarket unit and gave me a one year warranty. This year, I failed emissions for NOX. I showed him the report and he immediately said, You need a new cat--I'll replace it under warranty--no problem.

So, he replaced it and I passed emissions. However, it is very noisy, and rattles. It sounds like my exhaust has a leak, but the whole exhaust is fairly recent. He says he'll fix it, no problem.

But what kind of cat? Since I've had two consecutive bad ones from the aftermarket company--one failing within a year and the new one rattling to beat the band--I'm planning on going with an OEM. My original one lasted 12 years. What do you all think of this? Also, when I research catalytic converters, the Miller brand is always about $100 more than the typical aftermarket ones. Is the Miller the same as the volvo OEM?

Your input would be much appreciated...

Markus