my 2004 f150 is running rough and its not the sparkplugs and it turns off and backfires

Asked by Oct 11, 2014 at 05:32 PM about the 2004 Ford F-150 FX4 4WD

Question type: Maintenance & Repair

1 Answer

16,050

Problems could be many and varied. A backfire occurs either in the exhaust system or the intake system. But it occurs outside the combustion chamber/cylinders. Unburned gasoline exiting the chamber may ignite once it hits the hot catalytic converter. If a valve does not completely close prior to detonation it could also fire backward through the carburetor or intake manifold. Have the vehicle towed to a qualified repair shop for diagnosis. You can damage your vehicle with such a condition. It is possible the catalytic converter is already shot. No big problem unless your state test exhaust gases for annual inspection. In that event you will most likely fail.

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