First thing that comes into my mind is to replace spark plugs. And I have usually replaced air filter at the same time an d because you have a "new" car and don't know so much about the service history I migth suggest to change your fuel filter too.
But change your plugs and lets see then if it helps or not. 
- No-Pain -
__________________
Nissan Almera (equal to Sentra) 1997 1.6 litres
Mods so far:
-Added disc brakes to rear
-All corners have got new springs and shock absorbers (monroe reflex)
-custom made 4-->1 exhaust manifold with 2" piping -Some cool kameleont painting
-Head work done. Porting, some valve job (lightening, cleaning and polishing). Intake- and exaustports on the head totally re-designed and grinded.
-Some gauges: oil temp, oil pressure, fuel pressure, meter, lambda and external rev. meter with change ligth
-Free flow air-filter (calculated intake pipe lenght) with CAI.
-Lightened battery, moved to back
- No-pain -
|