On my way home from work today in my wife's MY'04.5 C230SS, I noticed the CEL came on and the engine begin idling rough. Got home, seached the forum and concluded the MAF may be bad or the vacuum line is leaking.

So I disconnect the MAF and restarted the car and it's still the same. Plugged it back in and immediately noticed the vacuum connector next to it had popped off for some reason with the collet still on the tube. So I remove the collet and put it back in the connector and now the connection is tight.

But the Check Engine Light is still on when I start the car...and the car is running smooth.

Does the CEL require some special MB tool to reset it? Or I may have other problem to deal with?

Please help!!

 

Yup...you need to go to MB or an independent MB tech to reset it. They have a handheld module that hooks up to your car "brains" and identifies what tripped the CEL and can also reset it from there...I had this done on my car back in January.

I'd go to an independent only because the service cost will be less...

 

autozone is free, loan a tool then reset it urself

 

I see.

Thank you AMGfan and KIRA for your quick reply.

I will try autozone tomorrow and report back.

 

yup go to autozone and use their obd2 scanner... hope its nothing serious... crossing fingers for you....

Anything like p0301 like that could be bad news..... i had p0302 and the dealership ended up replacing the engine head.. luckily i was still under warranty! thank god1

 

I borrowed the OBDII scanner from Autozone and cleared all the codes, no more check engine light

Very strange the vacuum connector pop off on it's own when driving.

 

I believe you dont even NEED to have it cleared. I think if you just waited a few days it woulda cleared itself, but glad to hear you've got it all under control. A little searching has yielded yet another success story