Have a rather annoying problem at the moment. My 2000 Mazda Protege's check Engine Light is on. Its been doing this every since I had my water pump changed. Tried changing my coil packs, cam shaft sensor, and had my catalytic converter checked and its none of those. Also is sputters and jerks really badly. I tried my changing my alternator and battery which made the problem less apparent and my engine turned off but the problem returned. Someone suggested my voltage regulator seeing its like my car isnt getting enough energy. Any suggestion would be greatly appreciated.

 

I'd stop throwing money at it. You need to read the code to determine what the problem is.

 

I have had all the codes checked and my car still is acting crazy.

 

Checking is not fixing the cause. What are the codes? P0something

 

Without the diagnostic trouble code, I'll take what you posted, and try to figure out what the issue is.
You think the alternator isn't putting out enough? The alternator has an internal voltage regulator. the only thing I read is you replaced the water pump, I assume this issue happened after the fact. If you are now having low voltage output, the only thing in common with this, and replacing the water pump is the serpentine belt. Is it slipping? How old /miles is the belt? What is the voltage output?