E420 Ehaust leak
 

Good Evening Forum Members,

I just purchased a E420 with 118K from a dealer, 09/07 production.
I did a short test drive, carfax and VIN check.
The car started up and drove fine until left to idle after the drive.
While idling the car began to misfire and stumble, no dash fault lights, i.e check engine came on. The low fuel indicator light was on so the dealer drove the car away to add premium gas. When he came back from the gas station the car was idling properly. He suggested that that was the problem.
I picked the car up today and while driving home, less than a mile from the dealership, I pulled over to let my son drive the rest of the way home. Again while idling the car began to missfire and shake. I detected an exhaust leak in the area of a exhaust pipe connection just after the cat. The words ELECTRICAL and CHECK ENGINE light came on and a strong rotten egg smell was apparent. I drove the car back to the dealer and left it for him to diagnose and repair.
Has anyone had a similar experience and fix or might know what the problem could be?
Can an exhaust leak cause these symptons and warning lights?
I'm nervous.

Thanks,

Knarf

I'm going to reach into near thin air, and guess coil pack gone bad.

Larry Delor,

Thanks for the speedy reply.
I don't know anything about these engines at the moment but plan on becoming knowledable soon.
I'm guessing that the coil packs will explain the rough running but what about the exhaust leak.
How does one determine which coil pack is bad?
I'm guessing that the exhaust leak is releasing the rotten egg smell of the catilytic converter.
But do all properly operating catilytic converters normally smell of rotten eggs?


Knarf

Usually a rich mixture is the culprit for stinky exhaust - it should not stink if all is in proper working order.

When the dealer checks the engine codes (check engine light), he will know where to look.