Looking to buy

I'm looking to get my wife a 2001 to 2004 Tahoe Z71. I was wondering if there is anything about these specific years that I need to look for. I had heard once that something about the 2001-2002 models had a poor rating on something, but I didn't know if that had any truth to it. And I can't remember what it was.

Any information ya'll could give would be helpful.