Q: The Check Engine Light came on, I hooked it up to my scanner and got the code P0308 (cylinder #8 misfire).

asked by on

Engine seems to run fine and I don't notice anything wrong with it when Im driving... do I need to replace my ignition coil or not? What else could be the issue? I don't want to waste money having someone replace my ignition coil if that won't fix my issue. I know my CV boot is cracked so could that be causing the problem?

My car has 121000 miles.
My car has an automatic transmission.

An easy way to isolate if the ignition coil is the problem is to swap the #8 coil with another cylinder. Swap the #8 coil with the coil from the adjacent cylinder, then clear the codes. If the code remains for cylinder #8, then there are other issues such as the spark plug, wiring, or a signal issue from the PCM. Also, an injector with a poor spray pattern can cause the misfire as well as a mechanical issue with cylinder #8 such as a valve or compression issue.

If the fault code moves with the ignition coil, then odds are you do have a bad ignition coil. If the coil is at fault, you may want to consider replacing them all at the same time. More commonly than not, when one coil fails, one or more will soon fail as well. Changing them all at the same time alleviates having to go through this 7 more times over the next several months. Otherwise replacing them as they fail is not a problem.

To avoid any unnecessary repairs, have a certified technician, such as one from YourMechanic, diagnose the Check Engine Light firsthand and help you resolve the issue.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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. The Check Engine Light came on, I hooked it up to my scanner and got the code P0308 (cylinder #8 misfire).

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: Timing kit squealing after new one was installed

It sounds like something might have been misaligned or not installed correctly during the previous service. I would recommend retracing your steps to see if any steps were not done properly or if any steps were missed. I would go...

Q: Engine knocking at higher speeds

Hello. A knocking sound during heavy acceleration could potentially be a sign of a serious issue, depending on where it is coming from. A knock from the engine can occur if it runs low on oil, and could quickly lead...

Q: I have a jerking ticking and popping noise when I accelerate what is it

Would need more information on the car and engine you have but the problem sounds like a misfire from the ignition system or carburetor problems.

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
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 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.