Unstable idle,rpm limited to 2500, 04 sentra se-r spec v

The rough idle is associated with the p011 code. The P011 code is: Camshaft A over advanced. There is a mechanical fault with the intake camshaft.
You need to take the car into a mechanic, preferably the dealer since they have all of the needed special tools, to properly diagnose and repair the issue.

Check the fuel pressure regulator diaphragm.
Do It Yourself Diagnosis and Repair

The rev limiter kicks in at about 6800 RPM to prevent "coast over" to unsafe revs, so I suggest you have a custom programmed PCM that eliminated the rev limiter feature or moves up the RPM limit.

Does the fuel gauge work properly? Recently had to have fuel sender unit replaced and Nissan dealership service to reset the idle learn on 03 Sentra SE-R Spec V. Engine idle rpm would go up and down as a result of bad sender.

Your Idle speed control or ISC needs to be replaced. Check for vacuum leaks.

i had a similar problem a few months ago with my se-r. i went to the dealership and had them reprogram the ecm and it fixed it(its on the recall list for your car.) once i did that everything ran great.

try replacing the crankshaft and camshaft sensers, my 2004 sentra spec v had the same problem.It cost me $122 for both the sensers and can be done in 20mins

Most times when you have a cut in power when the RPM's are high that's most likely a "SPARK" problem. However it can also be a "GAS " problem. Does check engine light come ON if it is or even if it NOT ON there can still be a Code stores in your computer. My first thing would be a BAD CRANK sensor/CAM sensor. This is my recommendations you should have this vehicle place on a code scanner/computer AUTO-ZONE does this check for free then get the codes if any is present and get back to me asap. I strongly thing it would be a crank sensor but if not there is a 20% chance its a FUEL PUMP can meet the demand when you hit the gas therefore then engine starves and dies. LEt me know how you made out. Good Luck and Thanks for using FIX YA

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