Q: Lost of power

Hello.

From what you describe it would appear that your vehicle may be experiencing more than one issue, possibly mechanical. Loss of power and fuel efficiency can be caused by many things. A few common causes are issues with the fuel, ignition, engine management, systems. If any of the components to these systems fail or have an issue they can cause performance problems.

If the Check Engine Light is on I would recommend retrieving the trouble codes with a scan tool as they will likely shed some light on what the issue may be.

Burnt oil smell is usually caused by an oil leak or engine mechanical issues. I would carefully examining the engine for oil leaks, and listening closely for any sounds that may indicate the possibility of mechanical issues.

As these sorts of issues can sometimes be difficult to pinpoint I would recommend having the loss of power diagnosed by a professional technician, such as one from YourMechanic, if you are unsure.