engine light is on the fuel consumption is too much?

Hello,

You could have a rich air fuel mixture ratio, that is what making the fuel consumption high.
There are number of reason for this to happen. It could be fuel, spark or emission related.
You could have a faulty oxygen sensor that is triggering the engine too run rich.

Since the engine light is illuminated, get it scanned for trouble codes. This could help determine what might be the issue.
You can take the vehicle to your local auto parts store and they can scan and provide you with the code(s).

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please let me know of any questions.
Thank you.