weird

ok check this out i replaced my pcv valve and i filled my 98 blaze up 1/4 and i dorve around 5 miles and my fuel guage started to go up like if i had more fuel in it or something, it went to the 1/2 fuel mark. I dont know what this couold be any suggestions.

PCV valve has nothing to do with the fuel gauge or the fuel sending unit in charge of gauging the fuel level.

The level in your take will go up and down when you accelerate and brake as the fuel moves around in the fuel tank.

ok cool but the guage did not suddenly go up and then decrese on and off it stayed in the 1/2 position for a while and after driving for about 5 minutes i went back down.

Fill the tank and see if it reads the level properly.

I have a problem like this on my Camaro. Its my summer car, so I am not that concerned about it cause its in the garage now. I did notice it, I can have like a 1/4 tank left and the guage will go up to like a 1/2 tank and back down. I think it has to do with something with the EVAP system, building to much pressure in the tank, it doesn't purge the vapors properly. Next spring I will tackle it.

EVAP system will not affect how the sending unit senses the fuel level.

yeah well i tried filling up the tank and it seems to be working like normal now. Hopefully i wont run out of gas thinking that i have 1/4 of a tank.