2000Cougar missing My car started mising so I changed all plugs and wires(plugs were very bad), But car still misses. What could be the problem?

runs like it's missing
Have scanned for trouble codes, could be dirt in a fuel injector or a weak/bad coil.

Your only solution is professional help & the use of
the proper professional tools, to first look at data &
see what' what's, then diagnose the issues

Changing parts at home with no system knowledge,
no reference material & no testing, is a wastes of time & money

more than likely spark plug leads,put new spark plugs first if problem carries on ,change spark plug leads if still persists get coil pack tested

Did you check the ignition timing ? It should be for manual transmission 20+/- 2 deg BTDC

automatic transmission 20+/- deg BTDC

FYI---One time i dropped a new plug before i put it in and did not realize that the gap have closed up and started a bad miss..make sure all plugs are gaped correctly....could be something else but you can start here...Hope this helped ?

Check proper firing order first then make sure u didnt sqish a spark plug? Did it miss fire before work was done?

Start with the simple things first. When was the last time you had a complete tune up? "Missing" could indicate bad spark plugs, bad spark plug wires, or bad cylinders. Change the plugs first, then go from there.

It likely needs plug wires.

missing on occasion? you changed the plugs? was it missing before are after you changed the plugs? Missing is usually caused by a spark failing to jump across the spark plug gap.i would first look for a broken spark plug insulator. Secondly, bad spark plug wires ( if you re-used them the connector might have pulled off the wire internally) also look at the coil and distributor for cracks or other problems if the plugs and wires check out ok .

It is probably a bad coil, have someone put it on a computer and see what cylinder is missing. The coils go bad all the time on the 5.4's

check the EGR valve it is open maybe