2004 Toyota Corolla

[Darren25]

Need help 2004 Toyota corolla 1.4 petrol problem idle is low  harder to start driving perfect but when stoped at traffic lights it rough idle shaking and vibrating inside cab I have engine code p0302 I have changed coils and also switched spark plugs still same way also changed injectors and cleaned throttle body spark plugs in cylinder 1 and two have black soot I am thinking maybe valve gasket is going any help or tips my two 02 sensors are working correctly I have tested them when I disconnect my Maf sensor car still on could this be the problem 

[Red_Corolla]

Not the valve gasket, but the cylinder head gasket could be a problem - that's based on your information that you have a misfire code and signs of poor combustion on two adjacent cylinders. I think a compression test would be a good idea - any good garage will be able to do that for you.

[kc88]

I had that issue with vibrating idle and random misfire in cylinder 4, put in Castrol gtx fully synth and had no issues, recently serviced with cheaper fully synth and its starting to misfire again now