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Q: Upon starting, loud noise from catalytic converter

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From how my car is sounding, I am thinking that the problem is probably the catalytic converter. After starting my car first thing, there is a terribly loud noise that sounds like marbles being shaken in a metal jar. Once the car is moving, the sound goes away. The day after this started happening, the exact same symptoms occurred. Finances are tight right now, so I'm wondering how long I can go before having to have this fixed. I would certainly appreciate your diagnosis. Before going to a repair garage, how long can I drive my car safely before I should take it to a mechanic?

A: If the catalyst is broken inside the conver...

If the catalyst is broken inside the converter housing of your 2001 Mercedes E430, then you may get some loss of power due to increased back pressure from partial blockage created in the converter. This can also lead to increased engine temperatures and possible overheating. The engine temperature will need to be monitored while driving, and this issue should be looked as soon as possible to prevent damage to the engine and to ensure that emissions stay within standards. You may want to enlist the help of a mechanic, such as one from YourMechanic, who can inspect the noise and determine the best next action.

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