someotherguy

This is on my 2006 Silverado SS - bone stock, 101K or so miles, have owned it since 80K. It didn't used to have any EVAP problems but developed them within maybe the last 5K miles or so, maybe a few more.

1. Got "tighten fuel cap" error on DIC. Checked cap, was aftermarket locking cap with badly cracked o-ring. Figured hey, no prob, I'll put a new OEM cap on it. Installed AC Delco # GT225 / 15763225 not exactly same style as the OEM cap on our other 2006 SS, but it's the part # that comes up when I search online.

2. Still getting error message and eventually get CEL. Also, noticed it's become difficult to fill the tank; pump wants to keep clicking off at first, got to keep re-trying until it finally starts taking full flow of fuel. Check codes, P0442 (small evap leak) and P0455 (gross leak) as expected. Did some research, found info about the vent solenoid getting messed up, and revised vent solenoid with remote mount filter. Installed revised vent solenoid and filter AC Delco # 214-2082 / 19207763, used an extra long length of hose to mount the filter way up front near the transmission vent hose. Didn't like the placement I saw others mention of putting it in the gap between cab and bed, seems like it can still get crudded up. Still getting error and CEL, and still difficult to fill tank.

3. Drive it like this for several months and get sick of looking at CEL and error, decide to look into it some more. Check codes, P0455 current code as expected, but P0442 and P0446 as pending codes, as well as P0455 shown pending. P0446 is evap vent control circuit. I do find it strange that I've been driving it for thousands of miles and some of those codes are just in pending status. Cleared the codes, and as an experiment, attached the filter to the vent solenoid with a very short (2") piece of hose in case the extra long hose was an issue, or possibly getting kinked along the route. Very next day, error message on the DIC, no CEL yet but I know it's coming.

So what's going on here...did I get a bunk new vent solenoid, or has my evap canister just gone bad? I didn't have this issue the first several thousand miles I owned this truck, and I don't have the habit of topping off the tank after the pump automatically shuts off. Trying to avoid spending $150 on a new evap canister just to find out it doesn't fix the problem. I'm not ready to blame the gas cap for anything since it won't be responsible for the tank being difficult to fill up.

Ideas? Thanks!

Richard

someotherguy

After nearly a week and just shy of 100 views I guess I gotta ask...nobody has any ideas? Doesn't seem like a topic that gets much model-specific discussion.

I think my next step is gonna be today I'll pull the evap solenoid loose from the canister and take the truck to put some fuel in...it's down to around 1/8 tank right now. That should hopefully show me whether it's a bad new solenoid, or a clogged canister, making fueling difficult.

Richard

3wide

Have checked the purge valve unit under the hood that pulls the fumes into the intake.? Not sure of the part # but I went through the same things you did on my 07NBS until one of the guys at work said to replace that out. I think it was like $30.00 and took less than 5-minutes to replace.

someotherguy

Thanks for the tip, actually hadn't thought about that at all as I didn't read about it being a suspect with the behavior and codes that I have. I definitely won't write it off though; I could stomach spending $30 and it not fix the problem vs. buying a canister and that not fixing it at $150..

Richard

Last Call

iTrader: (4)

If you have a scanner with live data, monitor the fuel tank pressure and see if it's leaking out. Evap leak DTCs are usually based on variances in actual vs expected pressure in the tank.

1FastBrick

iTrader: (17)

Silver Stripper giving you problems?

As mentioned, best way to diagnose would be with monitoring live data. I have seen the tank pressure sensor cause the codes.

Is the filler neck attached properly to the tank? Follow the rubber tube to the tank and make sure the clamp is tight.

Fill issues would likely be the canister or the vent valve.

If it's not pulling enough vacuum or if its not sealing and continuing to pull vacuum, the solenoid on the intake manifold could be the issue. The donor was rolled over and did have oil in the intake. Also pull the top cover on the manifold and follow the plastic line from the vent valve on the intake to the metal line at the rear of the block and make sure its attached properly.

bottledls6

iTrader: (2)

I have chased this problem in my own truck. Mine was the gas cap. But if I where you I would do a smoke test, see if any hoses are cracked. As for the difficultly of pumping gas it could be several things as you have stated already, but look at your charcoal canister as well. At times they like to let go, an some of the charcoal will cause hoses to get plugged up, roll over valves to get stuck open etc. But if that's not it, just tune it out an call it good.

someotherguy

Nope, it's the Redneckinator...

The fill issue has me leaning towards the canister, I just didn't wanna spend that $150 without doing some more detective work first.

I had already replaced the cap and evap vent solenoid/filter assembly prior to the fill issues cropping up; just dealing with the "tighten fuel cap" error message that started earlier.

Richard

1FastBrick

iTrader: (17)

Might still want to check that filler neck where it attaches to the tank. Was that the side that the bed side had to be replaced on???

If not the cap then the canister is likely the issue. Try disconnecting the vent line from the tank to the canister at the canister and see if the fill up rate changes. If it does then you will know the canister is bad.

someotherguy

Passenger bedside is what got replaced, but he had the bed off the truck to do it (as well as fix the dent in the back of the cab where the bed popped it.) I did consider that, thinking it was possible the lines got twisted or kinked when the bed got reinstalled, but the fill problem took a while to crop up after the repairs...so I'm thinking it's more likely the canister just went bad over time. Maybe got its life shortened by the impact of the crash? Who knows. When you buy the thing with 80K on it you just don't know if all those miles before you it belonged to a guy that had the habit of trying to cram all the fuel he could into the tank. I do this on the diesel work truck, but never on any gasoline engine vehicle.

Richard