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Q: I'm having a very rough idle and the cheek engine light came on in my 98 expedition 5.4L engine. Your guess at the cause?

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I'm in a 1998 5.4L engine ford expedition. Truck starts but odors rough with check engine light on and off, and also feels as if it's going to shut off during driving.

My car has 240 miles.
My car has a manual transmission.

A: Hi there: Although guessing on what could ...

Hi there:

Although guessing on what could be wrong isn't an ASE best practice method of fixing a mechanical problem, there are a few items that could be causing the rough idle. First, anytime a check engine light comes on, it's because a mechanical or electrical component has triggered an error code, indicating that a problem exists. By downloading those error codes first, a professional mechanic is able to trace the issues to one or a few individual parts. In most cases, the rough idle is caused by dirty or clogged fuel injectors, the throttle body being dirty or damaged, the idle control valve being damaged, or the EGR valve needing to be replaced or simply cleaned. To know for sure, contact one of our mobile mechanics to complete a car idle is rough inspection first. This way they can download those error codes and pinpoint the source of your engine issues and recommend the right repairs.

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