2003 nissan sentra ser spec v won't rev past 1900 without losing power and bucking. Any suggestions on what could be wrong

change transmission fluid and filter. Check for blown gaskets on valve assembly. Clean throttle assembly with anti soot fluid.

never wash or wet an air filter as it closes up the pores in the paper element
fit a new element and then run the fault codes or reset the ECM using a scan tool

Since the engine light is not on, I think you have a problem with fuel. Replace fuel filter and test again.

If it won't fit, they have the wrong part. I would go to Autozone, Advance Auto Parts, NAPA, or O'reillys and buy the thermostat from them.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

error p1446 is a closed control valve on evap .. that is located behind the tire on the drivers side .. you can sometimes clean that .. that can also be caused by a bad or loose gas cap ..

code p1456 means a small evap. leak .. there is a smoke test to help find the leak if you have trouble ..

P0650 Malfunction Indicator Lamp (MIL) Control Circuit Malfunction (computer)

Note - not a solution..just adding my woes!
I drive a 2003 Nissan Sentra SE-R Spec V.
My car suddenly stalled 1 day and the engine wouldn\'t turn over. Brought it to my mechanic and had the Camshaft position sensor replaced by my mechanic. The car ran fine for about 2 weeks and then the light was back on with the initial symptoms.

Took the car into the dealership and they diagnosed it again as P0335. Said that the mechanic hadn\'t installed the sensor correctly. Charged me a bunch of money to replace the thing and not too long ago the check engine light is on. The Revs bounce around everywhere. Checked the code again and it\'s P0335 yet again! Am in talks with the dealership to get to the bottom of this...

Sounds like a starter, or the solenoid for the starter has gone bad

Yes the flywheel can be turned unless it has been worn past specs but sometimes it is cheaper to get a new flywheel

sounds like a computer module problem . have the computer diagnostic scan done at your nissan dealer. good luck mister bill

I have the same car and I know there was a TSB for the ECM . I know the ECM issue has cause some cars to stall while driving