Weapon power-ups respawn immediately:
Press Start to pause game play and highlight the "Map" option. Then,
press Triangle, X(2), Triangle, Square, Circle(2), Square, X,
Square, Circle, Triangle. The sound of an engine will confirm
correct code entry. You still need to find where the original weapon
power-up appears, then collect it again. It will also cause some
weapons which you have not unlocked to appear next to your garage.
However, not all weapon power-ups are next to your garage. They are
usually nearby, but on a ledge or around the block.

Unlimited ammunition:
Press Start to pause game play and highlight the "Map" option. Then,
press Triangle, Square(2), Circle, Triangle, Square(2), Circle. The
sound of an engine will confirm correct code entry.

Money:
Press Start to pause game play and highlight the "Map" option. Then,
press Triangle, Circle, Triangle, Circle, Square, X, Square, X,
Down, Up. The sound of an engine will confirm correct code entry.

Restore health:
Press Start to pause game play and highlight the "Map" option. Then,
press Square, Circle, Square, Circle, Square, Circle, Square,
Circle. The sound of an engine will confirm correct code entry.

Decrease RIOT level:
Press Start to pause game play and highlight the "Map" option. Then,
press Triangle, Circle, X, Square, Triangle, Circle, X, Square,
Down. The sound of an engine will confirm correct code entry.

Increase RIOT level:
Press Start to pause game play and highlight the "Map" option. Then,
press Triangle, Circle, X, Square, Triangle, Circle, X, Square, Up.
The sound of an engine will confirm correct code entry.

All vehicles:
Press Start to pause game play and highlight the "Map" option. Then,
press Up, Down, Up, Down, Triangle, X, Triangle, X, Square,
Circle(2), Square. The sound of an engine will confirm correct code
entry.

Tornado:
Press Start to pause game play and highlight the "Map" option. Then,
press Triangle, Circle, X, Square(2), X, Circle, Triangle. The sound
of an engine will confirm correct code entry.

Hint: Exit the RIOT mode:
If you are getting beat up by the swarm of cops that come out in
full RIOT, go to the garage and park. The RIOT will be turned off.
To save your progress, you will have to pull into the garage again.

Hint: Other towns:
When you progress enough, you will be taken to another city by
following the "M" on the map. You can actually go back to the
previous city at anytime. Pay attention where the exits are for the
cities.

Hint: Extra power with EMP gun:
When you are charging up your EMP gun, wait a few extra moments
until you see a light blue ring appear around the energy ball. It
will keep your opponent disabled a few seconds longer.

Hint: Easy kills:
If a gang of cops or rival gangs are coming after you, learn to
drive and shoot in reverse. Back away from the cars that are about
to explode or the explosion will take off a tremendous amount of
armor.

Hint: Easy money:
Listen for the weather report on the radio. When you hear the report
for the tornado warning, find the tornado and follow it from about a
block back. You can pick up all the scavenger parts from the
vehicles that the tornado destroys. For extra cash, try to induce a
RIOT near the tornado. The increased traffic and constant stream of
cops will give the tornado more toys to toss around and give you
more cash.

Hint: Faster upgrades:
Stay by your garage and induce a RIOT by killing the civilians and
other gangs on the street. To get the RIOT factor up faster, blast
away the street cops. When your armor is running low, drop by the
garage and pick up a repair kit. Keep repeating this until you get
enough money for the upgrades. If you "fail" the RIOT, do not
restart by loading the previous save. This allows you keep all the
money, no game penalties will be levied, and you will keep all of
your upgrades. The only thing you will lose are all of your weapons