There are many reasons why your car is losing power. Perhaps, there's not enough fuel getting into the engine. This is likely if your car has a clogged fuel filter, dirty fuel injectors, or a bad fuel pump. Speaking of fuel, the combustion process that goes on in your engine is also depending on the ignition system. As such, worn-out spark plugs and faulty ignition coils could easily cause your car to lose power. Beyond that, a lack of compression would impact the combustion process. Similarly, clogged and dirty air filters would prevent air from getting into the combustion chamber to burn with the fuel.