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04JGCSpecialEdition 01-12-2013 02:21 PM

P 0303 misfire #3 4.0L
Hey guys, I have been having rough starts when the engine is warm. Today the engine light came on so I did the on/off/on/off/on and got P 0303, misfire on #3. I have changed the spark plugs maybe 5K ago. I have disconnected the negative terminal on the battery to reset it but what should I do if it comes back? I was thinking maybe the fuel injector? How difficult are they to change? If not the injector, maybe the coil pack? Looking for what step I should take first. Thanks

Frango100 01-13-2013 04:46 AM

Re: P 0303 misfire #3 4.0L
I would, to rule out the plug, swap it with an other position. At the same time you can check the color of the plug and if there is something strange at it.
You could take the injectors out and let them clean, then you also see if they are working correctly. The last step i would take is changing the coil rail.

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