what are the symptoms of fouled plugs?

[benhogan]

95 e320 wagon.

i recently had a bout of bag gas. the bad gas has been burned off and has been replaced by good gas.

the car runs better but it is still not a smooth as it was before. I am thinking it might be the spark plugs. do you think replacing the plugs is a good idea?

i've never done this task before to this car. I plan to use NGK unless you have a better recommendation.

what is the proper torque? any pitfalls to watch out for?

Please help. Coming from the diesel world, this is somewhat new to me.