Check Engine light on right after I filled up with gas. HELP!

[ALLBIZNISS]

I have 99 ML 320. We purchased it about 2.5 years ago. We have never had any problems. This baby has been "purring".

I have ALWAYS used Supreme gas as recommedned. We normally go to Chevron.

Today I went to fill up at Chevron as normal. I definitely used Supreme (91). As soon as I turned the car back on though, it shook a little and then jumped and the check engine light came on. It didn't go off, so I drove it right home. I turned the car off, and then turned it on again, to see if it would go off, and it didn't. Then I revved the engine and the car really started to shake.

Could it be the gas? Perhaps they had the wrong gas in the Supreme line?

It seems weired that as soon as I filled up this happened. Again, this car has had no mechanical problems or tell tell signs that maybe it may break down. I talked to a buddy of mine who said his Benz (E320) for some reason doesn't like Chevron gas, and the first time he used it his car wouldn't start. Another used regular gas and his car turned into a "putt putt"

What should I do? Am I stuck with going to the mechanic and paying for a diagnostic check? Is there anything else I can do?

[RestyB]

That recently happened to my wife's 02ML after a fill-up and at first she noticed the "low gas" indicator quickly flash and then stay on, and then the check engine light came on thereafter.

She immediately drove to the dealer and was told that she did not put the gas cap on tight enough. The service advisor also told her that the check engine light will stay on for a few days and then go off. I was skeptical, but sure enough three days later and the check engine light disappered.

This was our experience and I don't know if others went through this as well. I'd be curious how yours turns out.

Best of luck.

[surbenzolot]

If there is no further sign of mechanicall breakdown then just unplug the battery for about a few minutes then see if the light comes back on when you start it.Just to check if theres something still triggering the light.Or just get a obd2 reader then you'll know for sure whatset it off

[Benz4Dirt&Sky]

Remove your gas cap, then replace it.

Make sure you click it into place past the 4 clicks required.

The light will go off after a few starts and restarts.

This has happened to me several times when I haven't quite clicked the cap enough.

It is a fault that is generated by the emissions control system sensing that your tank isn't sealed tightly enough.

If the CEL stays on after you have driven around for a couple of days it may be something else.