It could be spark plugs or coil packs. Auto Zone will check your computer codes for FREE. This way you won't be guessing.
Not using premium fuel caused that in my 2004 Navigator.
It could be one of your vaccum lines that collapsed
lincoln navigator
Turn signal flasher module?
hellow just wonderin if you guys know where would be the heater core on my 2003 Lincoln navigator
Having no catalytic converter installed is illegal and can cause a myriad of problems. Probably not a backfire though.
brake switch located on the top of the brake pedal
That would depend on the year of your Navigator and Expedition. See the related link.
I would say NO ( I was looking at the 2001 Lincoln Navigator Owner Guide and it does not show anything about it having a cabin air filter )
There are several things that can cause your 2000 Chevrolet to backfire and die. The most common cause is a plugged catalytic converter.
on my 2000 town car it was the idle air control valve sounds like you have the same problem
On a Lincoln Navigator : Bank 2 is the drivers side of the engine * sensor 1 would be close to the engine BEFORE the exhaust enters the catalytic converter