Was it missing and sputtering before you changed them? If no, then you could have got the firing order mixed on the distributor. Maybe if you didn't replace the wires also one became more damaged while removing it. If yes, maybe its your fuel, or injectors, and you need to add a bottle of cleaner to your gas tank.
It is probably your spark plugs misfiring.
replace spark plugs and wires
the transmition ,is probably not adjusted to the spark plugs,or their not the right spark plugs
if it is an automatic could be spark plugs or spark plug wiring...if a manual check the fuel pump
change the spark plugs
One reason why your 1994 Nissan Altima could be sputtering at an idle is because of your spark plugs. It could also be caused by the idle sensor.
You need compression, fuel and spark. You are missing one of those.
Check/replace Rotor Check for spark at plugs
A 6-cylinder has SIX and a 4-cylinder has FOUR spark plugs.... Am I missing something here?
I would replace the spark plugs after 50K, the wires and plugs again at 100K.
plugged cat, but make sure you check your spark plugs and wires. If its time to change them , then change them first and drive the car. , if sputtering continues, check the cat and the ignition coil.
The spark plugs on a 1999 Mercury Cougar are located under the cover of the engine. The spark plugs should be changed approximately every 60,000 miles.