I have a 3.1 liter Grand Prix and it says low oil and after that all the light lit up and it tried to shut down on me, what's going on?
The low oil light comes on before anything else when the car is about to stall. All the other lights come on with the key on + engine stalled. You'll need to get the OBD code to trace what's going on. Get the car to PepBoys or Autozone, they will read the code for free. Take it from there - either find a mechanic or post the code here and maybe someone can point you in the right direction.
It doesn't have a check engine light on an isn't throwing any codes however it stalls and will not start most of the time unless I pump the gas. I unhooked a lot of the sensors just to see if it would throw a code for kicks and the light never lit up. Also the security light is on while its running which is also new.
If you got no codes with the sensors disconnected, it's possible that the ECM is bad. But before going that route, check the following: ISC - Idle speed control system (check for gummed up idle valve), low fuel pressure, vacuum leak (especially EGR). These can cause intermittent stalling or rough idle along with hard starting, but the engine will run fine at speed. You will need a special scan tool to run a proper idle speed control test, one that sends the vehicle-specific command to increase idle speed. If you don't have this, try turning on the A/C to the maximum setting, with the car idling. If you don't get an increase in RPM, the ICS is bad.
Okay, now I had replaced the original motor with a different 3.1 out of an 02 Buick century. Are the ECM's different?
Yes, there are variations in the ECM, mostly for the different vehicle weights and different trannys these popular engines were mated to. If the ECM is the one that came with the engine, you should be okay. It might affect performance or gas mileage, but I don't think it would affect the idle. If you kept the car's original ECM and hooked it to the new engines sensors, however, that could sure be a source of miscommunication.
Looking for a Used Grand Prix in your area?
CarGurus has 4,404 nationwide Grand Prix listings starting at $1,800.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts