Nissan: sticky accelerator

Sentra 2001 (30,000 miles) accelerator gets a little sticky. Dealer has
cleaned once and it is better but would like to know specifics if I
decide to do my self in future. Dealer at first send air filter was to
be changed at 15000 miles. I showed that ny manuals send every 30,000
miles (which I did) dealer cleaned at no cost. Good for him and me!.
Thanks in advance.
Lon