Skip the auto shop - Our mechanics make house calls

Q: Getting error code P0304

asked by on

My car appears to be running fine, though the Check Engine, Trac Off, and VOC lights are on.Using a reader, I was able to get error code P0304.

Since you are getting a misfire code on the #4 cylinder that will cause the computer to shut off these other systems. The misfire needs to be fixed first. Most of the time when this comes up it is caused by a failing spark plug or ignition coil. A mechanic would typically inspect and test these first before going further. If these parts are fine then a compression test will typically be done to see if there are any internal engine problems. I’d recommend having a mechanic determine the cause of your engine misfiring issue in order to make the repairs needed.

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: Can i put a 2000 toyota celica GT automatic transmission in to a 2002 toyota celica GTS

The only way to be absolutely certain that it will fit, is to make sure that it's the same part number, and that the mounting points are in the correct place. That said, many people swap different transmissions into their...

Q: Lifters knocking on a 2007 GCM Sierra

If it doesn't happen all that often, and it doesn't happen on high speed, but is just idling--I'd live with that if I were you. Because with that kind of miles on it, all those lifters are going to be...

Q: Cylinder number 4 is misfiring black dry carbon on spark plug code P0304

Hi there. It would appear you have covered all the bases replacing components for your P0304 engine misfire. As you already know, replacing components can be expensive and time consuming without resolution. Assuming the engine is mechanically sound, good cylinder...

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...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.