Hello al I have reached 100k on a 2001 Tahoe. I bought it with 97k 6 months ago so I am not sure of the history although I can say Its inexcellent condition and the engine is super clean. I changed spark plugs and wires about 3 months ago with OEM parts. I need some suggestions on what to have done for the 100k mark. I want to do a transmission flush but I have heard horror stories of trannys breaking down after that is done. I also am told that I need to change the "rear differential oil"? Also is there any kind of engine flush that is available so I can keep the engine in tiptop shape? Also my knock sensor just went bad according to the check engine readout from autozone. Whats the ballpark repair price on that? All comments welcomed and appreciated...-Joe-

 

I think any transmission that goes bad after a fluid change was bound to go bad. Do you have a 4wd where you might consider service on the transfer case? Sounds like that truck is gonna run for quite awhile with the proper maintenance you're putting into it. Good work!

Replace the knock sensor yourself.
http://www.jimfancher.com/sierra/p0332.htm