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Q: When I start my car up its a rattleing sound was thinking catalytic

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I start my car up and theres a ratteling sound that sounds as if its coming from the catalytic converter. I also can hear while running pinging like sounds as well coming from that area as well. Also smell of gas could this mean that my catalytic converter needs to be replaced. Car rides fine but I did notice a slight hesitation last time I drove it when accelerating.

My car has 161 miles.
My car has an automatic transmission.

A: Hello, the catalytic convertor can make tha...

Hello, the catalytic convertor can make that type of noise. Inside the convertor is a honey comb shaped element that the exhaust gases pass through. Part of that element can fracture and become loose within the shell of the convertor, causing the noise you are hearing. The convertor helps with exhaust emissions and is ineffective with this type of issue. The hesitation is created because of the exhaust flow being restricted within the convertor. The pinging noise is breaking down the convertor internally, there are metal particles blocking the path of exhaust flow out of the convertor. This issue will create loss of power, overheating and damage to the engine. The convertor will need to be replaced as soon as possible. If you'd like, a certified technician from YourMechanic can come to your location to replace your converter. Please look at this web site for more information and service options.

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