new to the board.. There are so many topics, I don't even know where exactly to post this, is it mechanical? OBII - troubleshooting, maintenance... who knows.

Anyway, I just bought this car, and I got the code P0440, changed the gas cap with a GM cap, about 100 miles later, code came back, the cap is TIGHT. I did a search, was wondering what to check out next? what'* this about rust in the filler neck? should I look for that, if so, what to look for and where exactly. Also, maybe the purge solenoid, how do I check for that, or just replace it and see if it helps. The way I look at it, I could probably replace all of my emissions parts MYSELF, even if only one of them has failed, and still end up paying less than whatever it would cost a dealership to do it @ $100/hr plus GM parts - GAG me! I have a firebird that is highly modded, I'm not new to cars, I do ALL my own work, and my last one was a '94 Bonne SE. I am new to this body style and the problems associated with it. please help!

I have the rusted hood, the bad gas gauge (which I already have the part on order for that) - watched the Youtube video on that one. I HAD the bad oil pressure sender, fixed that, got the clunking steering wheel, have the kit to grease that. Just fixed the WSS in the front hub/bearing now my TCS light is gone... one by one, I'm getting to everything.

*** Moved to Mechanical ~ Kevin ***

In your search, did you find this https://www.gmforum.com/t284087/#post1390980

yes, i found that... the problem is that I don't know what the purge solenoid is or where it'* located. I don't know what parts make up the 'canister' or where that'* located. And I don't know what the Evap sensor is or where that'* located. I also don't know which ones to try first, and/or if there is a way to do some diagnostics to figure out which one could be the problem. I know the dealership would fill the tank with nitrogen and visually look for leaks, however... I don't have a supply of nitrogen so I can't do that test.

Does anyone know where I might find an exploded diagram of the Evap system so I can study the parts and maybe figure out how to locate the different problem areas? Thanks much!

Unfortunately I know almost nothing about the evap system, b/c on any of my other cars, I've never had problems in that area. Sad... I would feel more comfortable replacing head gaskets on this car than I would be messing with the evap system.

Here'* the purge solenoid.

Spray carb cleaner on the vacuum lines to see if you have a vacuum leak.

10 days left until I'll be tardy for emissions inspection. We just had a new baby, so i've had little time to get this taken care of. I replaced the gas cap, still have the light on, I cleaned rust off the filler neck near the gas cap.... still on. I replaced a $30 cluster of vacuum lines that attach to the purge solenoid, and go to various areas like the FPR, and somewhere near the throttle body (they were all badly rotted and damaged)... light is still on.

TONIGHT.. i was pulling in, and struggling for any clue to what the problem might be, i heard some ticking sound coming from the engine bay. it'* definitely coming from the purge solenoid, I could hear a rapid ticking sound, I put my finger on the solenoid and could actually feel the ticking.. I unplugged the solenoid and it stopped. I don't know if this is normal, but anyway, the part is only $24 at my local parts store so I ordered it and will replace it tomorrow. Two of the lines connecting it are ones I replaced, just easy vacuum lines, but the last one is a fuel line, I think. are there any special tools required to remove this line?

Thanks!

Fuel line tools are not that expensive and a great tool to have in your arsenal. They slip on the line and then you force them into the retainer clip and the line pushes off.

I could have sworn what Danthurs was calling a purge solenoid was a vacuum pump. . . we had the fuel line come off it and it was clicking, and would stop as soon as I put the line to the tank back on. I will have to get out my dealer manuals tomorrow morning and look through them and see what I'm smoking. . . .

When we re-attached the fuel vent line from the solenoid/pump to the tank our problem was fixed. If you want I can try to get some pages from the dealer books and PM them to you.