I have a honda civic 2000 ex, and my check engine light is on...
code p0300-p0304 and 171
which means
random misfire
cylinder no 1-4 misfire
and fuel system is to lean
I have a platinum spark plug and someone suggest I should change the spark plug
and also the fuel injection because its dirty

is that true that i have to change both of them or is there any other solution?
thnx

 

or should I change the o2 sensor?
but how much is it to change o2 sensor?

 

Well as far as the misfire you should check your distributor cap for moitsure. don't know about the engine running lean but if your O2 sensor was goin bad it would be running rich. Good luck with the problem.

 

change your fuel filter.

 

my car did that and I needed a new fuel pump

 

haha, I got more confused now, more options on what to fix...
so what bout the cylinder misfire?

 

check you plug wire. by checking the resitance to see if they are good. the spec. should not exceed 25k ohms