Q: Sputtering problems

Hello. Engine sputtering and performance issues can be caused by many things. If you have already replaced those components then I would move on to looking at a few other things. Issues with the ignition, engine management, or fuel systems can all cause the symptoms you are experiencing. A few other ignition system components to look at would be the ignition coil and ignition module. Both of these components are vital to engine spark and can cause performance issues if they go bad. Other things that can cause similar symptoms are faults with the mass airflow sensor, fuel pump, fuel injectors, as well as a few others. The engine management system functions using a series of sensors and components to deliver the proper amount of fuel and properly timed spark, and can experience problems if there is an issue with one or more of the various components. As the possibilities vary greatly, I would recommend having a professional technician, such as one from YourMechanic, come to your location to diagnose what may be causing your sputtering](https://www.yourmechanic.com/services/engine-is-sputtering-inspection).