Hello guys over been having issues with my car. Check engine light came up it's a random misfire. Also I'm experiencing loss of power I replaced the sparkplugs and the old ones seem to be fine the coils look good. I do have valve cover leakege idk if it is related. My car has 83k miles.

 

Hey guys I have a random misfire code and I have a huge loss of power and leak from valve cover (maybe related?) Recently changed sparkplugs cleaned throttle body and mass airflow sensor, the coils seem ok.if I accelerate slowly is not too noticeable but once I hit it hard the car takes a while to respond. When I shift gears around 5000 rpm I lose around 1000 to 2000 rpm. Can anyone help? I'm taking it to a shop tomorrow for a diagnosis but I'm open to suggestions tank you gentlemen.

 

Get a code reader see which cylinder is bad. Swap fuel injector from a good one to the bad one and see if code follows injector if it does then you know injector is bad

 

Thank you sir. It's just a random it doesn't specify. Code
​​​​​​ is just too generic

 

Use code reader and find bad cylinder. Swap coil pack with good one and see if it follows the coil pack if it does then that's probably the issue if not check the injector

 

For those trying to help, a P0300 is a "random misfire" and that mean a specific cylinder is not identified.
So.... moving a fuel injector or ignition coil won't help, as you won't know if the misfire has moved.

I would check the fuel pressure. A special adapter is required (https://cj-motorsports.com/products/fuel-tap-npt-2-bolt) and a 100 PSI gauge.
Stock fuel pressure at idle should be around 51 psi.

Another option is to use OBD Fusion's diagnostic report and look at the misfire counters.
Sometime a P0300 is reported, but the misfire counter may be higher on a specific cylinder.

 

Im taking it to a shop in the morning for diagnosis. I saw a YouTube video whit same problem, he replaced the injectors and problem was fixed I might do the same.