2013 Smart fortwo Pure CEL P0455


Yesterday from the smart center of Rochester, MN I bought a 2013 Smart fortwo Pure with 19k miles. This evening the Check Engine Light came on and it is code P0455.

No other dash lights are on and I have not even touched the gas cap yet. Should I clear the code? Take it to the dealer? Tow it to the dealer?

Any help would be appreciated, thanks.

First think I would do is make sure the gas cap is tight.

If the CEL is lit-up steadily, rather than blinking/flashing, there is no reason to tow the car. A steadily-lit CEL means that something needs to be attended to as soon as you can get to it, but that it is not an emergent situation.

Now, as to what the problem might be, because that code indicates a problem in the evaporative emissions system, the first step is to remove the gas cap and then reattach it securely, making sure to allow it to click when you tighten it. Then, start the engine and drive the car through several “drive cycles”.

That means starting it, driving it at varying speeds, parking it and shutting off the engine, and then driving it again–repeatedly for a few of these cycles. More than likely, the CEL will turn itself off after a few drive cycles if a loose gas cap was the culprit.

If the CEL doesn’t turn itself off after several drive cycles, then–of course–you need to drive the car back to the dealership for examination. Surely this car is covered by some sort of warranty, so…Why would you NOT take it back to the dealership if simple self-help measures on your part are not effective?

After this is resolved, please post back with the outcome!

Should I clear the code and do you what you two suggest an see if it comes back on? Thats what the mechanic on justasnwer suggested. I will try checking the gas cap. Thanks!

Mercedes gas caps have a tendency for the plastic retainer in the center of the bottom side of the cap to shift position. Make sure that the saddles in the plastic insert are aligned properly with the metal tabs so that the tabs rest in their appropriate locations. The CEL will flash if the cap is not secured properly. If the CEL is activated constantly you have another fault occurring.

First think I would do is make sure the gas cap is tight.

Freudian slip? ;-]

Also check the mating surfaces of the gas cap rubber gasket. A light coating of Vaseline there will help. This worked for my brother last week for a P0446 code.

For an EVAP code to clear you will need the car off for several hours (like overnight) between each drive cycle, with the tank between ~1/4 and 3/4 full.
I would check/fix the gas cap and clear the code. Then see if it comes back in a few days.

This should still be under the manufacturer’s warranty. If it is, take it to the dealer and let them diagnose it. dealing with it yourself could jeopardize you warranty coverage.