I have an ongoing CEL light which reads both a P0442 and P0445 (Small and Large EVAP Emission Control Leak) as well as the reserve tank warning light flashes periodically. Would the Charcoal Canister Shut-off valve be the most likely source? If so, where is it located (2000 E320 Sedan) and how can I test? Any other suggestions (I've already replaced Gas Cap).
Thanks,
Alan