CanuckMerc

Just for those following along that eventually will have this problem (I've learned these past 3 years owing a 2001 E320 that it is almost inevitable)
So with my car it started day one after I bought it, a puncture in the gas tank that I didn't know was there and must have been plugged with gum or something let go. I had gas all over the garage floor and trailing out behind me like a cartoon as I made my way right to the mechanics. The check engine light was on and the flashing gas light was blinking. The gas tank was replaced as was the filler neck etc etc.
Then I had a problem with the gas cap, turns out the previous owners thought to remedy the situation by applying silicone to the inside. I replaced it with a new one.

Then the flashing gas light continued, and the check engine light never went off, even with a new gas tank, filler neck, hoses and new gas cap.
Then the replacement gas cap wouldn't come off, yep locked on like a son of a gun while I was MOVING from Canada to the US and filling up in Oklahoma. I was so pissed off, it took me 15 minutes but I managed to literally pull it off by hand. Replaced with a cap that was a Pelican Parts match but not a Mercedes cap so I never had that problem again.

However now I was in New Mexico and P0455 meant no registration for the car. Had to fix! I noticed the purge valve under the hood, disconnected it, blew on it, put it back on and the P0455 code disappeared. I ran the car right down to the emissions place and passed the test! Yay 2 years of registration by the hair of my chin. But then 2 days afterwards the flashing gas lamp came back and so did the code.

I replaced the purge valve with a new one, thinking that was the culprit based on the experience I had previously. No luck.
I then replaced the plunger valve on the canister and voila, the P0455 code was gone and so was the flashing gas lamp and the check engine light! Success I thought, I finally nailed it and after 2 years I finally had a car with no warning lamps activated.

Then almost 2 weeks later, the check engine light came back on. And to top that, when I filled the car full with gas, it choked and the engine wouldn't fire up, only turn over and over. I did a code check and found error P0446. Anything past a 3/4 tank fill and you needed to wait a few minutes before she'd be able to fire up.

I'm now a couple weeks away from another registration deadline and I'm about to tear out the charcoal canister, check the hoses for plugs and the wires around it to see if there's a poor connection, chaffing etc.

I will update as we go along and we're hoping that the Burgundy Beast pulls through finally. I love this car, she's a beauty!

cm60k

i think you have a bad charcoal canister shut-off valve..!,, did you check it..??

-;ZAYED;-

CanuckMerc

cm60k

Yeah bro.,

"P0455" mostly refers to somewhere leak in Evap. system,

but "P0446", for the shut-off valve, that attaches to the canister,,

it may gets clogged or leaks in one of hoses that plugged in it..!

-;ZAYED;-

CanuckMerc

CanuckMerc

Update.

Well I've pulled off the charcoal canister. There was no plugs in any of the lines to the canister itself. The lines to the purge valve to the engine, I blew into them and no plugs. The wiring to the plunger valve on the canister itself look good, almost brand new, no chaffing and the protective sleeve around the wiring intact.

However this unit that attaches to the canister, when I blew into that hose, there's definately a stoppage or plug. Does anyone know what this unit is and if I should have been able to blow air through that line sticking out?

Also one other question for those that know. Can I plug these lines and put the wheel shroud back on and drive the vehicle if need be?

CanuckMerc

Update. Car is fixed! No codes, no check engine. The last part to be fixed was that over the top evap check valve and I cleaned it out with MAF cleaner by spraying every port to excessive. I then blew and sucked all the ports....then sprayed some more! Then sprayed even more! Then I reinstalled. First time in 3 years this car is good to go with that danged yellow light trolling me!