I've had this same code haunting me for a while and I am due to get a state inspection, so I needed to fix it. I replaced the fuel cap at the AutoZone guy's advice, which did not fix it.

So, I saw this thread and was inspired to replace the sensor. It is much easier than okiedoak20 said. I only had to drop the spare out, did not have to prop my Envoy up. The sensor was easily accessed and came off with a little wiggling and the replacement went in without an issue. I reset the light by unplugging the battery for a few minutes and the service light hasn't turned back on yet.

I've only driven it for 5-10 minutes or so though. If it comes back on I'll try the hose replacement.

Thanks!

 

The service light hasn't come back on yet, and I just passed state inspection.

 

Ay yi yi! The garage we always use tried to screw me with the whole fuel pump for $500 with labor. We just replaced the darn thing two years ago!! Fortunately I went to another garage who let me know the sensor can be replaced as can the wiring harness. Guess I've found a new garage.

I'd do it myself but I've got a broken leg and just walking sometimes is a problem without even getting into getting down on the ground!

Glad, too, that I found this site.

 

I spent $40 to do it myself, picking the sensor up at AutoZone. The place I normally use quoted me almost $300 to replace the exact same sensor. It's pretty easy, so maybe you could talk a buddy into helping you for 20 minutes or so. I didn't need to jack the back up, just drop the spare tire out and I could get to the sensor pretty easily. I wouldn't replace the wiring harness unless the sensor replacement doesn't work, it doesn't seem likely to be the issue IMO.

-Brenton