I jus got a 2001 Civic Ex with Cylinder 2 and cylinder 4 are misfiring. When I test drove it the check engine light wasn't on about 2 miles later it popped up. I replaced the spark plugs it turned off for about 25 mins then went back on. Any ideas what it could be?

 

Use only OEM NGK plugs.

 

Yeah they are, gonna see and change the ignition coils next hopefully that will help

 

It may only be one coil so test them all first before replacing them all.

 

so is the plan to keep replacing parts? or at what point does one start troubleshooting? assuming you don't own any diagnostic equipment, at the very least logic would dictate to take coils 1 and 3 and swap them to cylinders 2 and 4. if the misfire returns to cylinders 2 and 4, we can safely assume the coils are not to blame? yes? yes.

 

went too 2 different mechanics one said my head needed a new gasket and vavles and was leaking. Next I went too another well known shop and they said the engine is basically going. All that can be done is too drive it till it goes out. Seems all can be done now is buy a new engine from Jdm and have it swapped. We unplugged each coil while the car was on there were all working, brand new coils, we unplugged injectors too and same there, I jus bought the car I am not paying for any of this the person bought from is.