Help with my 2001 VW Jetta

I was pulling into work this morning and once parked noticed that my car running rough. I turned down the radio to see if I could hear anything and when I did I could hear a noise coming from the back seat. I lifted up the seat and put my ear to the fuel pump and heard it and it sounded like it was straining. is this normal or could something be wrong? Is there something I should check like relays?

Now I will say that my car has been having problems and has a code of P0171 System Too Lean. The O2 sensors were replaced and the MAF was cleaned. The car runs great and gets great gas mileage around 30mpg highway in DC traffic. Now when the car is parked or at a light it is a little rough. Can anyone help with getting this fixed.

Mileage? Engine type? We need more information.

Is all maintenance up to date according the the schedule in the owner’s manual?

Sorry, 2.0 GLS 109000 miles and yes everything is up to date. last complete tune up was done Oct plug wires ignition coil. Fuel filter was replaced in Aug. The air filter is OEM replacement so no oil.

Check the fuel pressure…it doesn’t have to be very far out of (read lower than) spec to cause just the things you describe.