It could be a couple of things... First thing is have your computer read by a scanner. Auto Zone will read codes for FREE. And go from there. I had a similar problem on my 1998 Ford Expedition XLT, and it ended been bad spark plugs. And since I have the 4.6L on mines I had to change plugs and wires. Problem was fix. The 4.6L only has 2 coil packs too... But, since you have the 5.4L it could also be bad coil packs... There 8 coil packs on the 5.4L.
I'm not a mechanic / technician but I was looking at a picture on fordparts.com and it shows the mass airflow sensor located around the engine air filter assembly on the drivers side for a 2006 Ford Expedition
It does not have a mass airflow sensor.It does not have a mass airflow sensor.
It does not use a mass airflow sensor.It does not use a mass airflow sensor.
It does not have a mass airflow sensor.It does not have a mass airflow sensor.
On a 1999 Ford Expedition : The Mass Air Flow sensor is between the engine air filter and the large diameter engine air intake tube ( it is INSIDE a round shaped plastic housing )
It does not have a mass airflow sensor.
It does not have a mass airflow sensor.
It does not have a mass airflow sensor.It does not have a mass airflow sensor.
It does not have a mass airflow sensor.It does not have a mass airflow sensor.
Could be an exhaust leak close to the engine or a bad catalytic converter. It also could be a bad mass airflow sensor.
A Dodge Neon does not have a mass airflow sensor.
Your Hyundai Tiburon may be idling high and low due to several factors, such as a malfunctioning idle air control (IAC) valve, vacuum leaks, or issues with the throttle body. A dirty or clogged air filter can also affect airflow, leading to erratic idling. Additionally, problems with the fuel system or engine sensors, like the mass airflow sensor (MAF) or throttle position sensor (TPS), could contribute to inconsistent idle speeds. It's advisable to have the vehicle diagnosed to pinpoint the exact cause.