I have an 04 Z71 too. Just turned 200k recently. Runs great and I love it!
Just FYI... About 3-4 weeks ago, I got an ABS light on. Code was for right front ABS speed sensor. There were two other codes stored in history. All three related to the right front ABS speed sensor signal being missing, erratic or weak. The hub had been OK when two mechanics look at it in October and there weren't nay obvious signs of failure.
I figured, OK... I'll get to that speed sensor in the next few weeks. No rush. I had already replaced a bad sensor on the left and that cured my previous ABS light coming on at highway speed only. Whatever, nothing major.
So I thought! My right front hub failed about a week later.
Not looking freak you out or paint doom and gloom for you here. Just want you to be aware, that an ABS code really can be something related to the hub having too much slop in it, which is just before it fails. Don't just go replacing a sensor without giving the hubs a thorough inspection! Almost all new hubs come with new sensors anyway.
Here was my recent post on that experience...
The link below is good. The preview shows something unrelated in the thread...
I had NAPA Ultra-Premium Polymer Coated discs with NAPA Gold Premium ceramic pads on my Jeep. Going to those again for my Tahoe the next set of brakes needed. Discs looked like brand new, even after 3 salty New England winters! Pads were awesome. Greta stopping and practically no dust. The discs...
www.tahoeyukonforum.com