2000 Monte Carlo SS 3.8
 

I think your on the right track, but typically the symptom of a clogged EVAP canister is the gas pump nozzle constantly shutting off as you try to fill the tank, as if the tank was topped off. I had that problem with one of my '00 SS's until I replaced the canister. It didn't effect engine performance. You might have a problem with the EVAP vent valve, the hose between the canister and the vent valve, or one of the EVAP lines out of the canister. Where is gas leaking from? Near the driver side rear wheel well behind the tire, or forward of the fill cap under the car (between the gas cap and rear of the drivers door)? Can you see what piece it's leaking from?

That's the EVAP vent valve by the rear wheel. If your having trouble filling, the EVAP canister needs to be replaced. The fuel tank needs to be dropped to get to it.


Here's a video about the canister:




Here's a video with a vent valve on a pick-up, but the principles are the same.

To get to the vent valve or the canister itself? Because I don't need to drop the tank for the canister. I took my car to Auto zone the gave me a print out of error codes, P0446 EVAP canister vent blocked, P0449 EVAP vent solenoid control circuit malfunction.

I think you have a bad EVAP vent valve. It can also cause the nozzle to shut off. Gas wasn't leaking when my EVAP canister was clogged. The vent valve is easy. Remove the rear wheel for access. Remove the bolt that secures the clamp holding the vent valve to the car, remove the electric connector and hose and take out the vent valve. Reverse procedure to install.

Video:

I would definitely replace the vent valve first. It's a twenty minute $30 fix. The canister is a PIB $110 all day job.

BTW...Get the wire harness adapter when you get the new VV if it doesn't come with one. They changed the connector.