Q: Check engine light code for a misfire

asked by on

I have a check engine light the code was saying i had a misfire in cylinder 5 i replaced all plugs and wires did an oil change it runs a lot better and quiet but my gas milage is horrible is this normal i have mud tires on my.truck not sure if this is a problem.and i still have a check engine light on like i said it runs a lot better i also put a new air filter in why would my engine light still be on. I replaced everything i needed to for the code

My car has 245000 miles.
My car has an automatic transmission.

Hi there. A misfire code is set when the engine computer sees a slow down in one or more pistons due to incomplete combustion. This can either be from a lean or rich condition. The task at hand is to accurately determine what is causing the misfire. Check for a crack in the distributor cap or rotor and replace as necessary.

There could also be a leaking injector that is pouring fuel instead of misting. This may account for the horrible gas mileage although the mud tires may contribute.

If I’m not mistaken, this model also has a cold start injector. Verify if the location of the cold start injector is in line with cylinder 5 intake port as a leaking cold start injector would also cause the misfire in conjunction with the gas mileage concern.

I strongly suggest having a qualified technician perform an inspection to prevent replacing unnecessary parts. If you would like to have this done, a certified professional from YourMechanic can come to your car’s location to diagnose the misfire and follow through with repairs.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Check engine light code for a 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: My car keeps cutting off when I put it in reverse and sometimes when it idles.

Hi There, Based upon what you are describing and how the car responds to load, it sounds like you may have a faulty MAP sensor. The Manifold Absolute Pressure (MAP) sensor senses engine load and generates a signal that is...

Q: My truck keeps giving me the cylinder #8 misfire code

Hello. A continuing misfire on #8 suggests a bad plug wire, a bad spark plug, or possibly oil leaking down onto the #8 plug, shorting it out. Also, if one plug wire is bad, replace them all. Given your mileage,...

Q: Crank seal leaking

Hello! I suggest getting a second opinion of the source of the leak, because a crank seal will not leak a fluid other than oil. The leak may be from a transmission seal, which is located almost "face to face"...

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 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...
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...