A second male teenager accused of killing an Uber driver on the Fraser Coast last year has admitted to his role in the man's death.

Tye Wayne Porter was originally charged with the murder of Scott Cabrie, but on Monday he pleaded not guilty to that charge.

However, during a brief arraignment hearing in the Queensland Supreme Court, he pleaded guilty to the lesser charge of manslaughter, which was accepted by the Crown.

Appearing via video link, Porter also pleaded guilty to unlawful use of a motor vehicle, armed robbery and arson in relation to Mr Cabrie's death.

A co-accused boy, who was 17 years old at the time, pleaded guilty to Mr Cabrie's murder last month.

He also pleaded guilty to unlawful use of a motor vehicle, arson and armed robbery.

The teens' admissions came 14 months after the body of the 47-year-old was discovered at a boat ramp in Howard.

At the time, police said the pair were Mr Cabrie's rideshare passengers and that they had attempted to rob him at Pacific Haven.

During the robbery, the younger teen killed Mr Cabrie.

The pair then drove to Howard and dumped his body, after which they torched his car.

Both were remanded in custody and will be sentenced in Brisbane in July.