1996 Chevy Tahoe turns over but does not start, rented dianostic tool, it showed no codes

Give it a spray of starter fluid for a quick check to see if it is a no spark or no fuel situation.
If it starts......no fuel and most likely fuel pump has failed.
Listen at the fuel tank when just turning the key to run.......after it has been off for 10 seconds.......you should hear a prime cycle for 1 or 2 seconds.......a whirrrrr.

If still no start with starter fluid.....then most likely no spark.
The most common cause for "no spark" on your Tahoe is the crankshaft sensor (a easy part to change....it reads off the front crankshaft pulley ).....next is the ignition module...then coil.

If no codes came up, then the first thing I would suspect is the fuel pump. to check it, you can stand by the rear end of the truck while your friend sits inside and switches the ignition to the on position. you should hear a somewhat lous buzzing noise as soon as he switches the key on. it should buzz, then stop after a few seconds. if you cant hear it, then its probably the fuel pump thats bad. or, if you want to be positive about it, remove the fuel line from the throttle body. careful though, it may still be pressurized, hold the fuel line over a bottle and have someone turn the key to on again. you will have a strong stream of gas coming out if the pump is good. if its very weak or none at all, then definitely replace the pump. if the fuel pressure is good, then look into the ignition module in the distributor. thats a common problem with these engines as well, and if I remember right, thyre not too expensive. other then that, I cant think of anything that would cause a no start and not set off a trouble code. either way, I wish you luck.

Yep, completely agree that it's a fuel pump, didn't state your mileage, but most go out 130-150,000 miles on this model ... complete pain in the rear to replace as you have to drop the gas tank to do it!