3800 SC Engine stumbles and cuts out

[UltraBuick]

Hey everyone,
I'm new here and I was wondering if you all could help me out. I have a 2000 Buick Park Ave Ultra with 174,500 miles on it, and for a week now the engine out of the clear blue cuts put of stumbles either under normal acceleration or while coasting. The rpm's drop and rise and the sometimes the oil pressure and voltage do as well. I'm not sure what it could be, granted I do have service engine light on but it is the general emissions evap code P0440 don't think that would effect my engine has not since it came on. Please let me know what you are all thinking, Thanks.

[HotZ28]

Welcome to AF! When is the last time you replaced wires, coils, or plugs? Have you checked for vacuum leaks?

[UltraBuick]

The Plugs and wires are good been on the car for 50-60 grand. The vacuum lines on the engine are good no leaks, I was wondering if it had to do with the Emissions evap code. It does it at random times where the rpm with drop and the engine will cut out. I got 2 senors for the engine the cam position and crank position sensor but I don't know if that would fix the problem. I'm stumped.

[Bassasasin]

I own the same car. My failing crankshaft sensor acted dramatically. It felt like the transmission locked up if I was cruising when the transmission was in OD or direct drive to the engine. A couple of big jerks and I was coasting to a stop. If it occurred when I was more off the throttle and at lower speed, say in town, it was more like a loss of fuel. Nevertheless it would cool and run again and never failed until the engine was warm. The gauges went irratic at the same time. Replacing the sensor was a 100% fix. The codes were Camshaft sensor codes.
Thinking:: If the RPM gauge gets its input from the sensor's output it would go to zero at the time of the cut out. If during the cut you press the accelerator and there is any power at all, it would seem the circuit is operating. :: Bass