I've read a couple years ago that a few years of the duramax production were prone to being problematic. IIRC those years are 01, 02, 03 & 04 but correct me if I'm wrong. A friend at work is looking to buy a duramax and I just want to steer him clear of any of the years that are prone to having problems. I think he's looking at an '02 right now. Which IIRC is the worst of all 4 or the problematic years.