Ms. Fire Is No Hot Date
Saturday July 5, 2008
Ms. Fire sounds like every guy's fantasy, but when she shows up unexpectedly, there are no smiling faces. She usually brings a Check Engine light with her as an annoying sidekick. Darrell has been getting visits from Ms. Fire recently and is ready to be rid of her. Here's his situation:
Diagnostic codes state a misfire on #2 cylinder of a 2004 Nissan Sentra with 1.8 liter 4-cyl engine. I have changed the spark plugs and the ignition coil, but the Check Engine light came back on. I checked the code again, and it stated that #2 is misfiring (again). I twisted the gas cap to see if that would help. So my question is, what else could be causing the same problem after changing the parts specified?Darrel, you were headed in the right direction with your troubleshooting. A visit from Ms. Fire (of course we're talking about an engine "misfire") is no fun. Those coil packs are about $75 each, so hopefully you only replaced the #2 module. This should have fixed the issue. Be sure to reset your check engine light to let it reanalyze the situation. You can remove the negative cable to the battery overnight to do that. There were also a few TSBs (Technical Service Bulletins) issued by the manufacturer for the 2004 Sentra regarding ECU issues, which could also be a cause. Check with the dealer to be sure your car has been updated.
Comments
thatskinda a crock o s$%t, see nissan has always, had a fuel injector issue. i would look there. kudos on saying to clear thecode, but you also clear emission data too, so no smog for you anytime soon. look into the fuel delivery compression area if replacing spark did not fix it. diagnosis by elimination isn’talwaysthe best way, ie. replacing parts.
Jason - Good advice about troubleshooting via replacement. Testing is always a must. Clearing the code is fine, most systems have enough data for a smog test within a day or two.
Great advice, but if you disconnect the negative cable to the battery overnight you will not only erase the trouble code but you wil also erase all of the freeze frame data that will be needed if you’re car is headed for the shop!
Jason - True, but if the problem is fixed, who cares? If the problem was not fixed, you’ll get a code back in no time, so it’s a win-win. It doesn’t take much road time these days to gather the data.
You said you replaced the coil pack and the spark plugs. If #2 is misfiring did you check to see if there is a crack somewhere in the sparkplug wire and the spark is jumping to the motor mount or valve cover?