2001 nissan sentra 2.0

Have you taken a look at the Spark Plugs? Check the gap on the plugs.

Since you replaced the distributor you may need to adjust your timing.

Visually check the air cleaner, intake hoses, ducts, Exhaust Gar Recirculation (EGR) valve operation and electrical connections prior to the adjustment of the ignition timing. Correct or repair any problem as required. Be sure to inspect the throttle valve and the Throttle Position (TP) sensor for proper operation.
1.Before servicing the vehicle, refer to the precautions in the beginning of this section.
2.Locate the timing marks on the crankshaft pulley and the front of the engine.
3.Clean the timing marks. (Point the timing light at the crankshaft pulley to see the timing marks — 1.6L and 2.0L engines)
4.Using chalk or white paint, color the mark on the crankshaft pulley and the mark on the scale which will indicate the correct timing when aligned with the notch on the crankshaft pulley.
5.Attach a tachometer to the engine.
6.Attach a timing light to the engine, to No. 1 cylinder’s ignition wire.
7.Check to be sure all of the wires clear the fan; start the engine and allow it to reach normal operating temperatures.
8.Block the front wheels and set the parking brake. Shift the transmission into NEUTRAL for automatic and manual transaxles; do not stand in front of the vehicle when making adjustments.
9.Perform the following procedures: A.Race the engine at 2000 rpm for about 2 minutes under a no-load condition; be sure all of the accessories are turned off.
B.Perform on board engine diagnostics and repair any fault code.
C.Race the engine 2–3 times under no-load, then run the engine it for 1 minute at idle.
D.Stop the engine and disconnect the Throttle Position (TP) sensor.
E.Race the engine at 2000 rpm for about 2 minutes under a no-load condition; be sure all of the accessories are turned OFF.
F.Run the engine at idle speed.

10.Aim the timing light at the timing marks. If the marks on the pulley and the engine are aligned when the light flashes, the timing is correct. The correct ignition timing is as follows: ◦1.6L (GA16DE): 6–10 degrees Before Top Dead Center (BTDC)
◦2.0L (SR20DE): 13–17 degrees BTDC
◦2.4L (KA24DE): 18–22 degrees BTDC

11.Turn the engine OFF and remove the tachometer and the timing light. If the marks are not in alignment, proceed with the following steps.
12.Turn the engine OFF.
13.Loosen the bolts that secure the distributor just enough so it can be turned.
14.Start the engine. Keep the wires of the timing light clear of the cooling fan.
15.With the timing light aimed at the pulley and the marks on the engine, turn the distributor for the proper adjustment.
16.Race the engine 2–3 times under no-load, then run the engine it for 1 minute at idle.
17.Aim the timing light at the timing marks. If the marks on the pulley and the engine are aligned when the light flashes, the timing is correct.
18.Tighten the bolt that secures the distributor and recheck the timing.
19.Turn the engine OFF and remove the tachometer and the timing light.
20.Connect the TP sensor.