I've had the flashing gas gauge and check engine light with P0455 code for several months now. Both indicate a gross leak in the evaporative emissions control system. I finally got around to investigating the problem since I was already digging in my engine compartment to change the intake hoses and clean the throttle bodies. I think I found and fixed the problem. I was hoping it was something simple like a disconnected or damaged hose, and I did find a disconnected hose as I traced the hoses from the throttle bodies backward.
Here are some pictures:
This is the right side showing the throttle body, the evaporative emissions control system hoses which connect to the charcoal canister located in the trunk, and the purge valve.
Here is the left side picture of the same thing.
The valves open up periodically under control by the car's computer. This opens up the charcoal canister to the intake which draws the gasoline vapors off the charcoal in the canister and into the intake to be burned. This process renews the charcoal so that it can continue to trap evaporating gasoline vapors. The whole idea is to reduce hydrocarbon pollution by preventing gas vapors from escaping to the atmosphere.
And here in the center of the wiring harness tray is where the two hoses from the purge valves meet up with the main hose going back to the charcoal canister. This pic is exactly how I found the hoses, disconnected.
I simply reconnected the hose with the T-connector. I'm thinking it may disconnect on its own again in which case I'll put a clamp or zip tie on it to hold it in place. I did note a bit of tension as I was reconnecting. It's possible that heat has caused a bit of shrinkage in the plastic tubing. Well, hopefully this will do it. I'll have to drive a bit to see if the P0455 code stays away. Although my car is an S600, all models will have the same parts that I have shown (just arranged differently), and disconnected or damaged hoses will be a possible cause of this fault in any car.