Charcoal canister shut-off valve?
I have a 1994 SL320 with a check engine light for code PO441 (Purge control valve function), which I got from the MB dealer that I had look at the problem. I have replaced the purge valve as I believe it had died. It was full of carbon particles from the canister. The new valve I installed also had some particles in it after a short time, but I cleaned it and it is still OK (I think). I have spliced in a fuel filter to keep the particles out for now. When I blow into the tubing that goes to the canister from the Purge valve I can hear a rushing sound coming from somewhere below the Purge valve. I have checked the canister and the three tubes appear OK as does the canister. I do not hear any leaks in that area. I think the sound is probably coming from, or near, the canister shut-off valve, but I don't know where it is located. Can anyone tell me where it is and how do I access it?