While he does get into some trouble, particularly in the later seasons, he never commits a crime severe enough to warrant jail time. His biggest trouble comes from his drug use and his relationship with a troubled girl named Julie Mayer.
The most serious trouble Porter faces is when he gets involved in a hit-and-run accident that results in Julie's father, Karl, being injured. However, even though he initially lies about it, he eventually confesses and doesn't face any serious legal consequences.