[neon_rt]

My 2000 GC 3.3l had a problem that sounds like yours at 85,000 miles.
Turns out that the "100,000 miles" oem plugs like to quit working one at a time starting at about 80,000 miles. I had the plugs changed, injectors cleaned, de-carbon the cylinders and throttle body cleaned. Ran as good at new after the tune-up.
My 2000 GC 3.8l didn't start missing until about 120,000 miles. Had a tuneup, runs like new.