I am experiencing the same problem with my wifes 01 Impala 3.8 with 87k miles on it. I have pulled the truck carpet back, removed the plate and access seems to be very straight forward. The only thing I am a bit nervous about is working with fuel and ensuring that there is no fuel pressure when I start to take things apart. If I simply remove the fuel pump fuse and run the car till it quits, then remove the fuel cap, is that good enough to guarantee that fuel wont go everywhere when I take this apart?
Second question is parts availability. My local Chevy dealer has told me that I must purchase the entire "sending unit" and the part alone is $180, plus they want another $200 for labor. Seems like a lot of money for something that appears relatively simple. I am going to call Napa and others but is this a dealer only part? Can the fuel sensor switch be obtained by itself as it appears that is most likely the problem here.
Thanks in advance for any help.