Check engine light on idling rough

Check for vacuum leaks from any hoses under the hood. Is the check engine light on? If so, retrieving any trouble codes may be helpful in solving this problem

Check the coils, there may be a bad coil. That lets moisture in it, and causes the engine to mis fire. God-Bless! Its worth a try!

run the fault codes to ensure that the EGR valve is faulty. Engine lights to not always come on unless there is something drastic going on with the engine /gearbox so that you can stop the car before damage is done.

It's not likely the plugs. Please get a scan at your local parts store, write down the trouble codes, and post them here.

Compression check may tell you something.

Could be a fuel pressure problem or one of the O2 sensors.
Is the check engine light on ?

if engine light is flashing it is not firing on all cylinders. a scanner will tell you what cylinders are misfiring. could be plugs. coil or other problem

there is a tps located on the intake where the inlet tube for air intake connects, it would be on the left side of the throttle body. does the trk run rough on idle? up/down sputter sometimes stall? Is check engine light on? if no light,check all vacuum lines for cracks/splits loose fit. do this by spraying carb choke cleaner on connections motor rpms will change if leak is present. also spray around perimeter of intake housing where mates with lower intake if engine revs you have bad intake gasket.I Just replaced upper and lower intake on my 98 and shazaam, runs like it should. but do your checks first,unessasary fixes are costly and **** you off.

the check engine light means that a code has been set. the code will reference a faulty system that must be diagnosed and repaired. sorry for the vagueness, but there are e gads of codes that can cause the rough idling

most aftermarket parts places will scan the car for free. this will give you an idea of where to start.