Skip the auto shop - Our mechanics make house calls

Q: Car struggles to accelerate

asked by on

The car ran fine until recently it struggles to even get to 40mph. The car is noticeably lounder and sounds under streas when accelerating. I changed the spark splugs and the coil pack and it did nothing for my problem.
My car has an automatic transmission.

This may be a sign of a clogged catalytic converter. As you may already know, the catalytic converter converts toxic exhaust gases into less harmful pollutants that are suitable to be expelled into the atmosphere. When this is clogged, this causes these gases to be backed up into the exhaust system not allowing the engine to breathe properly (think of a backed up sink). When this happens, the engine I forced to work much harder to expel these gases. This often results in the engine bogging down and causing very poor fuel economy. This should also cause a check engine light to come on as the O2 sensors should be reading the incorrect amounts of oxygen in the exhaust gases if this is your problem. I would recommend having an expert from YourMechanic come to your location to diagnose and replace your catalytic converter.

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!
  1. Home
  2. Questions
  3. Car struggles to accelerate

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: Oil leak

Hi there. Engine oil is crucial to properly lubricate your engine's moving parts internally. An engine may seize without the proper lubrication in the system. Your oil may have leaked from your oil pan, oil filter spindle, or in some...

Q: Front suspension lower arm bolt no. 2

Hi, thanks for writing in. I'd be happy to help. If the bolt head has in fact separated from the bolt, this may require drilling the bolt out of the control arm as there is otherwise no way to put...

Q: Will a 2002 ford mustang motor fit a 2005 mustang

If you want to swap the 2002 and 2005 4.0 engine then there should be same basic engine will be the same but you will have different external components that will need to be swapped out to match the car...

Related articles

How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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...