Distributor issue should be like other sensors, it should(?) trigger the CEL.

What did the old spark plugs look like? Check against this...
http://www.ngksparkplugs.com/techinf...q/faqread2.asp

Take off the intake duct, check out the throttle plate. Get some TB cleaner & wipe out the bore where the throttle butterfly closes. Dirty crud preventing it from closing completely? Then check & clean the idle valve (IACV) on the back of the intake manifold.

I just looked for a picture but Majestic's site is messed up. I choose throttle body & it shows me the radiator fan. I choose intake manifold & it shows me coolant hoses. Maybe later...

Also check your PCV valve. It should be like a little plastic elbow stuck in your valve cover. Take it out & see if it's plugged with crud. Shake it, there's a little plug on a spring, it's supposed to rattle. Or just buy a new one, they're like $10.