Skip the auto shop - Our mechanics make house calls

Q: Engine misfiring

asked by on

After replacing the battery the computer has relearned the correct idle setting, but now my engine is misfiring. I have cleaned the throttle body but that hasn't helped.
My car has an automatic transmission.

A: You need to scan the engine to see if one p...

You need to scan the engine to see if one particular cylinder is misfiring. Then check the cylinder for a fouled spark plug or plug wire. After this is done, clean the fuel injectors. The injection system injector may be sticking. Also, you should clean off carbon on the engine's valves and injectors tips. If you need some help with this, consider YourMechanic, as one of our certified technicians can perform these checks and accurately diagnose your misfiring issue firsthand.

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・Save up to 30%

Get a quote

What others are asking

Q: Clunking/popping sound while turning and going over bumps

Hello. It sounds like you may be having an issue with one of your outer tie rods. The outer tie rods connect the power steering system to the wheels. These tie rods are ball joints but they are not the...

Q: Car won't even turn over.

Hello, the first thing to check is the base engine and make sure it will rotate by hand with a ratchet and socket. If the engine doesn't turn, further diagnosis will be need done to see why the engine won't...

Q: Noise coming from the engine compartment followed by blown engine

An engine failure is definitely not good news. Engine failures can be caused by numerous things (e.g. low oil pressure, contaminants in the intake, etc.). Thankfully the 2007 Optima is covered by Kia’s 10 year, 100,000 mile power train warranty....

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
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...
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...