If you have an automatic transmission: You won't simply "put oil back in" after changing the filter. You'll need to drain the transmission fluid completely, replace the filter, and then refill the transmission to the correct level. The amount of fluid required varies depending on the specific transmission in your 2003 Pontiac Grand Am SE.
You cannot rely on a single number. You absolutely must consult your owner's manual for the correct procedure and the precise amount of transmission fluid required. The manual will detail the location of the fill point and the method for checking the fluid level (often using a dipstick, but sometimes other methods). Using the wrong amount of fluid can severely damage your transmission.
If you have a manual transmission: There's no filter to change in the transmission itself. You only change the gear oil, usually through a drain plug. Your owner's manual will specify the amount needed.
In short: Find your owner's manual. It's the only reliable source for this information. Using an incorrect amount of transmission fluid can cause significant damage.
