06 Impala Tighten Fuel Cap

I have an 06 Impala LT with the 3.5. It keeps telling me to tighten gas cap so I went ahead and replaced it. It's still triggering a code. I'm thinking about changing the purge valve and vent solenoid next. Any info you guys can give me is appreciated.

more likely the tubing under the gas tank for return of fumes.

You have an evap leak...the very first place to check is the gas cap, therefore, that's why that message comes up...it may save you a trip to a garage.....

If the cap seal looks ok, and there is no rust on the mating surface of the fill tube, and you turn the cap 3-5 clicks, and the code comes back, then you have a leak elsewhere.....

Could be a bad vent or purge solenoid.....could be a bad line/tube(connection or break)anywhere between the intake of the engine and the gas tank.....could be a leaking canister.......leaking fuel tank or seal to it....if you live in a heavily salted area(winter), underneath that fill tube could be rusting/leaking....the leak could be so small, it's hard to pinpoint by smell because of wind currents around the vehicle.....

The only way to fix it fast and without wasting parts, is to go to a dealership/reputable garage and have a smoke test done.......this test seals the system and then pressurizes it with smoke, and where you see smoke, you see a leak.....

Yeah, there are way too many valves and parts to test on these systems. Just get the system smoke test for $100 or however much they charge and save yourself a lot of headache and money.

Update: I was told by a friend at the dealership that the vent solenoid located behind the driver side rear wheel are no good. I bought a new one but they revised the design so you have to get a jumper cable. I ordered the parts, it cost me $40 and about an hour. I reset the code and haven't had any trouble since.

Update: I was told by a friend at the dealership that the vent solenoid located behind the driver side rear wheel are no good. I bought a new one but they revised the design so you have to get a jumper cable. I ordered the parts, it cost me $40 and about an hour. I reset the code and haven't had any trouble since.

So nice of you to come back and post to share with us your resolution. Most people get their problem taken care of and forget to share the details on how to get it fixed.

So I want to thank you again for that!