Bad coil, wire, plug. Fouled plug, vacuum leak.
This could be bad spark plugs or plug wires
There are several things that can cause your 2003 or Expedition to misfire. The most common cause is a plugged catalytic converter.
Yes.
It could.
A defective aspirator valve would unlikely cause a misfire monitor failure. It would more likely cause an air system monitor failure
If you have an automatic, the fluid level is low or the filter is dirty.
I'm not a mechanic / technician but it might be the spark plug , spark plug wire , not the proper air / fuel mixture to that engine cylinder , and there are probably other causes
what would cause the ADVTRAC OFF light to remain on on my 2005 ford explorer
faulty distributer, not hard to change ------------------------------------------------------------------------------------------------------------ I was just wondering if you changed the spark plug wires one at a time ? Otherwise, it could be quite easy to have a mixup on the coil pack.
If you have a "check engine" light on, start with having the codes read. A misfire code can tell you which cylinder or cylinders are having problems. A misfire could be the cause of your engine vibration.
It means that more than one cylinder has a misfire history. PO301 would be cylinder number 1 misfire. PO302 would be number 3 cylinder misfire.
Sounds like a misfire caused by electric supply to plugs.