Answering "How do you change oil pump on 1999 plymouthy neon?"
It is the connection between the lower radiator hose and the water pump.
most likely a faulty fuel pump.
The filter is located in the pump, on the gas tank.
You will need to use the Haynes repair manual, Dodge Neon 2000 thru 2003. Book #30036 I used it to change an oil pump and it helped alot!
Dodge does not use inertia/reset switches.
The gas tank has to be removed to get at the access panel for the pump. The tank is reused.
In the water pump on the 1999 grand prix gt internal?
How to change a water pump on a 1997 Pontiac Transport
the 98 and 99 Plymouth neon's do not have a fuel filter, they have a fuel screen that right in line with the fuel pump. I found this out only yesterday when I was had to replace my fuel pump. If your car is not starting and blowing fuses for the fuel pump, you need a new fuel pump.
The water pump on that neon is located in the distribution belt with between the camshaft and crankshaft pulley, you have to change also the belt, the problem with that is that it is really difficult to remove the crankshaft pulley, you need a very special extractor for that. Removing the water pump is really easy.
The fuel pump on a Neon is inside the fuel tank.
The only way to access the water pump on a Neon is to disassemble the passenger side of the engine.