Ok, guys, my gas gauge has started to act up. I did a search and cannot get the link on prior threads for this sensor fix. I went to the Tristar radiator thread for the sensor part they sell for like 90.00.
Here is what its doing. Staying on full. Gauge sweeps back after shut off. Turn on key, goes up to full. Sometimes it will come down to what position it should be at for a few seconds then shoots back up.
If you guys guess this is that common problem and if that link I cannot get to is the instructions for the fix, please shoot me those instructions.(I have a 2000 SSEI)
I appreciate all the help you guys have done for me!
Thanks so much!
Danny

common problem, here ya go https://www.gmforum.com/t278816/

Thanks so much!!! My car has 115,000 and I am sure its the problem. Doesnt look to hard, just wait for a cooler day. Thanks!!! Saving me a ton of money!!

Just did mine a few weeks ago with the Tristar sensor unit. The unit they sent me was not the same as the one on my fuel pump. On the plastic housing that holds the PCB and the pivot point for the float, mine has a single snap tab in the center attaching it to the fuel pump. It was a different configuration on the one they sent me. I ended up taking the PCB and pivot arm off the one they sent me, and swapping it out to my old one. Works fine.

The entire install was very easy. The only tricky part is removing the lock ring that holds the fuel pump to the tank. Be patient, and alternate hitting tabs on opposite sides of the ring, and it will come off. You don't have to whale on it like some threads say you do. I used a hammer and screw driver. Make sure you buy a new gasket for the fuel pump. I got one from Rockauto.com.

By the way, none of this will make sense to you until you have your fuel pump out and in your hand. Reading this post when you are physically looking at the fuel pump will make everything clear. Feel free to PM me if you get stuck, and I will send you my phone number, and walk you through it.

Roy

Mine works great until 1/2 tank. Then it wanders from full to empty. So for now it gets filled up when we reach 1/2 tank. Dealer wants over $550 for a complete pump and about $250 for sender alone. And no that'* not installed prices! I won't be going to the dealer for that part. When I get to it, I'll change out the complete pump because with almost 180000 miles I would hate to change out the sender and then the pump quits after I get it all put back together. Good luck,
Mike

Thanks 2KGU! Didnt think about the seal! I think I will get the Tristar unit as its improved. I will grab a seal from Rock Auto also. Thanks for the advice on the ring too! Right now just using the trip odometer. Waiting for the weather to cool off! Its mid Sept here in Utah and feels like July! Usually its down in the 70'* by now.
Thanks again!!

I have an '01 SE. The gas gauge works normal until 1/2 tank than goes near full.

I have found that if you put the key to ON (engine not started though) The gas gauge SHOWS THE RIGHT LEVEL. I don't know if that will work for anyone else or not. As long as I can check the gas level that way, I'm not worried about replacing the sensor.

This seems strange, but it was my experience:
I had similar problems with my gas gauge, I found it to be "inconsistent". I tried a can of BG44k at the reccomendation of a friend and it fixed my problem for about a week. So instead of throwing down the money to fix it properly, which I didn't have at the time, I let it go and I was way careful about hitting gas stations frequently. A few weeks ago, my mechanic was working on my car and told me I was in need of a fuel filter, so I just had him do it out of convienence. As it turned out, the filter change fixed my gas gauge. Doesn't make sense to me, but it works now, and is has for about 6-7 full tanks since the filter was replaced.

That'* bizarre.

What did your gas gauge do when it was "inconsistent"? For example, on mine it would read full when I knew it was empty. That was more than inconsistent, that was out of the ball park.

I know it doesn't make any sense, but I swear it is working now.
My gas gauge was usually a little high, but it would shift around depending on the level in the tank, but it was never correct. Often times it would read full, other times 3/4 when I knew I was empty, other times it would read correctly (although not often).