Skip the auto shop - Our mechanics make house calls

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

asked by on

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.

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: What is knocking noise?

Hello, thanks for writing in about your Dodge Ram 1500. If you pulled the cylinder 4 plug wire and the noise got quieter then this is an indication that you have a bad rod bearing or piston pin on the...

Q: My car crank but does not start.

Hi there. Check the camshaft position sensor and see if it has failed. Usually the engine will start and run with a partial failed camshaft sensor, however, when the sensor has failed completely and lost communication to the computer, then...

Q: The car loses acceleration intermittently

Hello. It would be recommended to have the vehicle looked at by a certified mechanic. They should have the specialty tools and techniques to identify the problem and repair the situation correctly, and avoid any damage or injury. This could...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...