Help- P0301 Code

[Naxa]

Yesterday, I got the P0301 code upon starting up my 08' Yaris Sedan. About 7 months ago the previous owner of my car changed the spark plugs (they did not change the coils). About 4 months ago, the CEL flashed above 3000 RPM, the engine was running rough, and I turned the car on and off and I did not have this issue, and eventually the light went away.

I cleared the code yesterday and the engine has been running with no issues ever since, so I cannot get the misfire to happen consistently, only rarely.


What is my best course of action?

[iOLO]

Chances are its the coil or spark plugs. If you want to be proactive you can switch the plugs and packs on cylinder 1 with cylinder 2 and see if the code trips p0302 down the line. Might also be a good idea to check the plugs anyway to see condition to ensure cylinder 1 isnt leaking oil on plugs or if its warn out. Might wanna change the coil for 1 either way if spark plug is clean.

[bronsin]

Simple. When it comes back swap coils see if it comes back with the coil you installed in the air code. Then change to a new coil.

Or swap spark plugs and read the code when it comes back. Then buy a new plug