Use the following codes after pausing the game (you have to select the Cheats option):
Babylon Club Redux mission: S13
Cabana Cigar/Oakely Drive-In mission: DW_FRON
Deliver mission: S12
Freedom Town Redux mission: S07A
Marina Storage mission: F_M_SHA
Nacho Contreras mission: S09
Nacho's Tanker mission: S10
The Dock Boss mission: A51
Un-Load mission: S11
Full health: MEDIK
Full ammunition: AMMO
1,000 Balls: FPATCH
Repair vehicle: TBURGLR
Decrease cop heat: FLYSTRT
Decrease gang heat: NOBALLS
Increase cop heat: DONUT
Increase gang heat: GOBALLS
Ariel MK III race car: OLDFAST
Bacinari: 666999
Bulldozer: DOZER
Odin VH88 dump truck: DUMPER
Bodog Stampede: BUMMER
"The World Is Yours" song by Breal: TUNEME
Black suit: BLACK
Blue suit: BLUE
Blue suit with shades: BLUESH
Grey suit: GRAY
Grey suit with shades: GRAYSH
Hawaiian shirt: HAWAII
Hawaiian shirt with shades: HAWAIIG
Sandy shirt: SANDY
Sandy shirt with shades: SANDYSH
White suit: WHITE
White suit with shades: WHITESH
Change time of day: MARTHA
Lightning: SHAZAAM
Rain: RAINY
Commit suicide: KILTONY