Hi All,

My 99 has thrown up P301 - Cyl 1 Misfire 3 times recently - twice after stalling (the girlfriend driving!!) and once after getting "a bit sideways" coming out of a carpark.

It's not noticable when it happens, just the code appearing.

Anyway, I changed the plugs to see if it helps. When I took the existing ones out, they look like below (cyl 1 on the left) - it looks to be whiter than the other 3. Having done a bit of reading up, this is either running too hot, or oil deposit? Or is it just because it's an old plug?



Would appreciate any thoughts!

Cheers
-keith

*edit* Just found the FAQ section on misfires - very useful! Fingers crossed the new plugs will solve the misfire - still be interested to know on thoughts for the plug looking different, though!

 

How many miles on the plugs?

 

They look way to old to even read.

 

That crossed my mind. I bought the car last September and have done about 10k miles since then. No idea when they were last changed!

 

those plugs look done. Change them and see if that changes anything

 

agree. lots of discolouration and buildup. hard to see the electrode wear from your angle.

 

Cheers guys. Codes were cleared with a reader when they appeared - definately not a consistent misfire as it took weeks to come back. Plugs were whipped out for new ones. I must admit, I was pretty embarrassed at how bad they are when I pulled them out!

 

plugs look consistent for about 5-8 years of use, not worth reading at this point in time, but they are all nice and dry which is good. These cars run a bit rich, so they are consistent with that based on appearance. I would not say number one plug is too white, it could be a touch whiter than the others but not much. Each cylinder has a different amount of airflow despite best efforts to even them out, cylinder one likely gets a bit more air flow, and cylinder four might get a bit less. Looks like it was a good time to change them either way.

 

^what he said. Due to the intake manifold having one point for air, runner irregularities ect, the VE of each cylinder is different.

I have a new set of NGK iridiums sitting in my room waiting to go in mine. The AP1 has 98k on it, so I'm hoping they've been changed by the previous owner and won't look that bad.

 

Thanks again for the replies. Haven't turned a wheel with the new plugs yet but it's on track on Sunday so I'll need to give it a run out tomorrow!

H22 to F20 - That's what I did! H22 civic to the S2k. S2k wins