Ignition Misfire Trouble Code Vague
 

I have a 2000 Civic CX with 77K miles on it and the check engine light is on. I had it checked with Autozones ODBII code scanner and was given an error that said Ignition Misfire / OE Control. About two months ago I got the same error code and did a tune up (cap, rotor, wires, and plugs) then reset the ECU and the light went off and stayed off. Eventhough I have the Honda Care warranty that should cover it if the problem is a sensor I really don't want to take it to the dealership b/c I know they will charge me a fortune no matter what the problem is. Anyone have any suggestions as to what might be the cause?
Also, I should mention that the car isn't running badly at all, I would'nt worry so much about it but with the car in open loop mode I went from 4-cyl gas-mileage to 8-cyl gas-mileage.

RE: Ignition Misfire Trouble Code Vague
 

Hi welcome to the forum, Im moving your topic to "General Tech Help" because this section is pretty much for saying you new and stuff like that. Try looking into Irridium spark plugs.. that is pretty much a good strong currrent to the cylinders.

RE: Ignition Misfire Trouble Code Vague
 

Wow, that is a tough one. Ok well, like mentioned before, welcome. Now I am not sure what could be causing it exactly and if the light is off right now(which from your post it appears to be, but you still showed signs of concern) then it was probably due to a worn out ignition component. The most common causes for misfires are improper gap(either from not gapping them correctly of just plain old wear and tear on the center electrode with time), bad ignition wires, bad/worn cap, or bad/work rotor. A weak coil or bad ECM can also cause that, but we will leave those as less likely to be the cause(but still a possibility). So if the CEL doesn’t come back then you may have already taken care of the problem. Now about this mileage issue, first I would have to ask what did the spark plugs look like when you took them off? If they were whitish on the tips(look at any manual with illustration for a better description) your engine might be running lean. During open loop your ECU will not compensate for the air/fuel mixture and it goes off a default table which means if you did any mods or there is anything wrong with your fuel/air delivery system it will be running off an improper mixture and it will degrade your fuel economy. Running lean can cause major damage to your engine. the white on the spark plugs would indicate high temperatures in your combustion chamber and while not making your coolant temperature rise, it will start cooking your engine internals. I don’t want to scare you, but you should have it look at. While running rich is not as bad, it still have its downfalls. One way(but not the only sign) you can tell if you are running rich is if you see black smoke out of the tail pipe when you floor it. This will not only kill your fuel economy, but lower the life expectancy of your cat. Depending on how rich it is running other things can happen as well. If you are truly seeing that kind of bad gas mileage I would take it in for testing with a wideband O2 sensor. It could be something really simple to fix. Oh and just to give you more things to look at, a bad cat can also give you poor gas mileage if it is clogged. Good luck and keep us posted.

RE: Ignition Misfire Trouble Code Vague
 

Update.... I took the wires off to check the plugs and they ripped apart... again so I went and bought Honda factory wires (much better quality) and tried to put those on thinking that the longer wires would have a higher resistance and cause the spark not to be able to jump the gap. Well the light went off for a few minutes and came right back. So I went to Autozone and had them scan the codes again P1336 came up. It says that the Crankshaft Speed Fluctuation sensor had an intermittent interruption. Also code P1399 has come up which I haven't been able to find an explanation for as of yet. So I've made an appointment with the dealership to have it checked out since the warranty should cover sensors. When I know for sure what the problem is I will let you know. Thanks for looking at my problem and giving me suggestions.

RE: Ignition Misfire Trouble Code Vague
 

Yes tell us so we will be able to help out future questions in this case.

RE: Ignition Misfire Trouble Code Vague
 

After taking the car to the dealership the problem turned out to be the wires leading to the crank position sensor had been worn through by the fan belt. This caused the connection to be cut and once the wires were replaced the car is fixed. It's running better than ever (probably due to the new AEM intake more than the car being fixed) since I got it back.